%42) *OURNAL VOLUME NUMBER /CTOBER $EVELOPMENT OF THE "ASE 3TATION 4RANSCEIVER
3UBSYSTEM IN THE #$-! -OBILE 3YSTEM
$ONG7OOK ,EE +ISUK 9OO *IN3U +IM -YOUNG *IN +IM AND *AE(ONG 0ARK
#/.4%.43
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)
).42/$5#4)/.
))
#$-! -/$%- !3)# !.$
2%#%)6%2 $%3)'.
4HE BASE STATION TRANSCEIVER SUBSYSTEM
"43 OF THE #$-! -OBILE 3YSTEM IS INTER
FACED TO MOBILE STATIONS OVER THE AIR AND TO
THE WIRED NETWORK THROUGH A PACKET SWITCHED
INTERCONNECTION NETWORK 4HE POTENTIAL BEN
E`TS OF #$-! TECHNOLOGY ARE ACHIEVED WHEN
THE TRANSMITTER AND THE RECEIVER ARE PROPERLY
DESIGNED AND IMPLEMENTED 4HE PHYSICAL LAYER
OF THE AIR INTERFACE AT THE BASE STATION IS IM
PLEMENTED WITH THE #$-! !3)#S AND CON
TROL CIRCUITS IN THE CHANNEL CARD OF THE "43
7E PRESENT THE DESIGN PERSPECTIVES AND STRUC
TURAL ILLUSTRATION OF THE "43 "ASE STATION MO
DEM !3)#S AND THEIR CONTROL TO IMPLEMENT
THE #$-! RECEIVER BASEBAND AND 2& SIGNAL
PROCESSING BLOCKS AND "43 CONTROLLER ARE DE
SCRIBED %LABORATE POWER CONTROL IS ESSENTIAL
TO ENSURE THE HIGH CAPACITY WHICH IS ONE OF
ADVANTAGES OF THE #$-! TECHNOLOGY 4HE
CLOSED LOOP REVERSE LINK POWER CONTROL AND THE
FORWARD LINK POWER CONTROL OPERATED IN THE
"43 ARE DESCRIBED
))) 3934%- !2#()4%#452% !.$
/0%2!4)/.3
)6 "!3% 34!4)/. 42!.3#%)6%2
35"3934%6
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2%&%2%.#%3
%42) *OURNAL VOLUME NUMBER /CTOBER ) ).42/$5#4)/.
4HE #$-! MOBILE SYSTEM #-3 A
COMMERCIAL PROTOTYPE DIGITAL CELLULAR SYS
TEM BASED ON DIRECT SEQUENCESPREAD SPEC
TRUM $333 #$-! TECHNOLOGY HAS BEEN
DEVELOPED 4HE BASE STATION CONSISTS OF BASE
STATION TRANSCEIVER SUBSYSTEM "43 BASE
STATION CONTROLLER "3# AND BASE STATION
MANAGER "3- "43 PROVIDES RADIO LINK
TO THE MOBILE STATION -3 )N THE FORWARD
LINK "43 ENCODES AND MODULATES THE INFOR
MATION DATA THEN TRANSMITS THE SIGNAL TO
THE -3 OVER THE AIR )N THE REVERSE LINK IT
DEMODULATES AND DECODES THE RECEIVED SIG
NAL FROM THE -3 THEN SENDS THE RECOVERED
DATA TO THE WIRED NETWORK 4HE BASIC AIR
INTERFACE FOLLOWS 44! ;= +OREAN STAN
DARD ON DIGITAL CELLULAR WHICH IS BASED ON
THE )3 A .ORTH !MERICAN DIGITAL CELLULAR
STANDARD ;=
$ESIGN 2EQUIREMENTS
'ENERAL REQUIREMENTS FOR THE DESIGN OF
#-3 ARE SUMMARIZED AS FOLLOWS
I #HANNEL 3TRUCTURE
4HE FORWARD AND THE REVERSE LINKS EM
PLOY CONVOLUTIONAL CODING INTERLEAV
ING PSEUDORANDOMNOISE 0. SPREAD
ING 7ALSH COVERING OR MODULATION
103+ OR /103+ MODULATION AS DE
SCRIBED IN 44! OR )3
II 3ERVICES
!S A BASIC SERVICE A VARIABLE RATE VOICE
SERVICE IS ACCOMPLISHED USING A DYNAM
$ONG7OOK ,EE ET AL
ICALLY VARIABLE DATA RATE VOCODER AL
GORITHM 4HE #$-! SYSTEM MUST
HAVE THE ARCHITECTURE WHICH CAN SUPPORT
SHORT MESSAGE SERVICE ' FAX OR DATA
SERVICES
III 2ADIO ,INK #APACITY
4HE CAPACITY MUST BE GREATER THAN TIMES OF !-03 CAPACITY
IV (ANDO_
4HE SYSTEM MUST SUPPORT SOFT HANDO_
WHEN THE MOBILE IS IN THE BOUNDARY OF
TWO BASE STATION COVERAGE OR SECTOR COV
ERAGE 4HE FORMER IS CALLED INTERCELL
SOFT HANDO_ AND THE LATTER IS CALLED
INTRACELL SOFTER HANDO_
V 3ECTORED #ELL
4HE BASE STATION SHOULD BE ABLE TO BE
OPERABLE WITH UP TO SECTORED CELL CON
`GURATION 4HE SECTORED CELL CAN BE IM
PLEMENTED WITH DIRECTION ANTENNAS AND
IS SHOWN TO GIVE HIGHER CAPACITY
VI 0OWER #ONTROL
4HE SYSTEM MUST SUPPORT THE FORWARD
LINK AND THE REVERSE LINK POWER CONTROL
VII 2EDUNDANCY
&AILURES OF SOME MODULES MAY CAUSE
THE ENTIRE SHUTDOWN OF THE BASE STA
TION #RITICAL MODULES MUST BE DUPLI
CATED AND THE SYSTEM SHOULD BE ABLE TO
DETECT FAILURES
VIII %XPANDABILITY AND -AINTENANCE
4HE SYSTEM SHOULD BE ABLE TO SUPPORT
UP TO FREQUENCY ASSIGNMENTS &!S
$ESIGN 0HILOSOPHY
4HE FOLLOWING ASPECTS ARE CONSIDERED FOR
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER THE DESIGN OF "43
I "ASE 3TATION 3YNCHRONIZATION
3YNCHRONIZATION IN #$-! SYSTEM IS VERY
IMPORTANT IN THE SENSE THAT ANY CHIP INTER
VAL DISCREPANCY CAUSES FATAL E_ECT TO THE OP
ERATION OF THE ENTIRE SYSTEM 4O SEARCH A
MOBILE STATION IN THE ACQUISITION MODE OR
IN THE HANDO_ STATE THE BASE STATION MUST
KNOW THE ABSOLUTE TIME "OTH BASE STATIONS
INVOLVED IN THE SOFT HANDO_ MUST BE SYN
CHRONIZED WITH EACH OTHER &OR THIS REASON
EVERY "43 IS EQUIPPED WITH '03 RECEIVER
AND CLOCK GENERATION UNIT
II &RAME 3TAGGERING
4HE SYSTEM IS GIVEN A DELAY BUDGET TO MAKE
A NATURAL CONVERSATION POSSIBLE 3INCE WE
DESIGN THE BASE STATION WITH PACKET SWITCHED
NETWORK AND THERE ARE `NITE NUMBER OF
TRUNKS BETWEEN "43 AND "3# QUEUING DE
LAY IS INEVITABLE
4O INCREASE THE TRUNK
UTILIZATION WITH GIVEN DELAY BUDGET FRAME
STAGGERING IS USED 4O SUPPORT THIS FUNC
TIONALITY "43 AND "3# MUST BE ABLE TO
HANDLE THE STAGGERED FRAME
III 3OFT AND 3OFTER (ANDO_S
&OR THE INTERCELL SOFT HANDO_ THE DIGITAL
SPEECH IS TRANSFERRED FROM THE VOCODER OF
THE MOBILE TO BOTH BASE STATIONS AND FROM
THERE TO THE "3# WHERE THE FRAME OF BETTER
QUALITY IS SELECTED PRIOR TO VOCODING /N THE
OTHER HAND IN THE INTRACELL SOFTER HANDO_
CASE COMBINING OCCURS IN THE "43 BECAUSE
THE #$-! !3)#S MAY PROCESS SIGNALS FROM
TWO SECTORS
IV &AULT -ANAGEMENT
4HE SYSTEM IS ABLE TO DETECT DEVICE FAULT
AND TO REPORT THE STATUS TO THE "3- )F
A FAILURE OF DUPLICATE DEVICE IS DETECTED
THE STANDBY MODULE UNDERTAKES THE ROLE
OF THE FAULT DEVICE &AULTS ARE CATEGO
RIZED INTO GROUPS DEPENDING ON SEVERITY
AND ALARM GOES O_ FOR THE CRITICAL FAULTS
V 2ECEIVER 3ENSITIVITY
3ENSITIVITY IS A MEASURE OF HOW WEAK A
SIGNAL CAN BE AND STILL BE RECEIVED SAT
ISFACTORILY )T IS DETERMINED BY INFORMA
TION DATA RATE TOTAL INTERFERENCE AND
REQUIRED %B .O ! TOTAL INTERFERENCE IS
A FUCTION OF THERMAL NOISE OTHER USER
INTERFERENCE AND OTHER CELL INTERFERENCE
!ND THE REQUIRED %B .O IN THE DEMOD
ULATOR DEPENDS UPON THE CHANNEL CONDI
TION %VEN IF THE INFORMATION DATA RATE
IS `XED A RECEIVER SENSITIVITY IS DECIDED
BY THE REQUIRED %B.O IN THE CONSIDERA
TION OF TOTAL INTERFERENCE
VI (IGH 0OWER !MPLI`ERS (0! /UTPUT
3TABILITY
! #$-! SYSTEM IS A NOISE LIMITED
SYSTEM THAT SHOULD CONTROL THE OUTPUT
POWER IN THE SENSE OF REDUCING THE OUT
PUT POWER BY THE MINIMUM REQUIRED
LEVEL 3INCE THE (0! IS A NONLINEAR SYS
TEM WHOSE POWER GAIN IS DECREASED BY
INCREASING THE INPUT POWER ITS POWER
GAIN MUST BE CONSTANT TO MAINTAIN THE
REQUIRED CELL COVERAGE 4O SATISFY THIS
REQUIREMENT THE INPUT POWER OF THE
(0! SHOULD BE CONTROLLED BY SOME TECH
NIQUES 7E PROVIDE TRANSMIT POWER
TRACKING LOOP AROUND THE (0! WITH A
POWER DETECTOR HAVING A TEMPERATURE
CHARACTERISTIC
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER VII $ATA ,OGGING FOR 0ERFORMANCE %VALU
ATION
4O EVALUATE THE PERFORMANCE OF THE
#$-! SYSTEM CERTAIN MODULES OF
"43 AND "3# CAN LOG DATA FOR POST
PROCESSING 0ERFORMANCE MEASURES ARE
FRAME ERROR RATE &%2 POWER CON
TROL ERROR VARIANCE STATISTICS OF TRANSMIT
AND RECEIVE POWER HANDO_ STATISTICS
ETC 4O MEASURE THE NECESSARY STATISTICS
`NGER ENERGY POWER CONTROL THRESHOLD
TRANSMIT DIGITAL GAIN COMMON AIR INTER
FACE #!) MESSAGE AND OTHER DATA ARE
LOGGED
LOCATION 4HE "). IS A PACKET ROUTER BETWEEN
"43 AND "3# #ONTROL AND TRAbC PACKETS ARE
PASSED TO THE DESTINATION THROUGH THE "). &IG
URE SHOWS THE BLOCK DIAGRAM OF THE "43
&IG "LOCK DIAGRAM OF THE "43
/VERALL !RCHITECTURE OF "43
4HE "43 IS COMPOSED OF 2& UNIT DIGITAL
UNIT "43 INTERCONNECTION NETWORK "). AND
"43 CONTROL PROCESSOR "#0 4HE 2& UNIT
CONVERTS THE RECEIVED 5(& SIGNAL TO )& SIG
NAL WHICH IS DOWNCONVERTED TO THE BASEBAND
4HE RECEIVED BASEBAND SIGNAL IS CONVERTED INTO
)) #$-! -/$%- !3)# !.$
2%#%)6%2 $%3)'.
"ASE 3TATION 2ECEIVER
! "ASE 3TATION $EMODULATOR 3TRUCTURE
DIGITAL SIGNAL AND DEMODULATED IN THE DIGITAL
/N THE REVERSE LINK THE INFORMATION DATA
UNIT 0. DESPREADING 6ITERBI DECODING DE
IS CONVOLUTIONALLY ENCODED BLOCK INTERLEAVED
MODULATING AND RAKE COMBINING OPERATIONS ARE
MODULATED BY THE ARY ORTHOGONAL MODULA
PERFORMED IN THE CHANNEL CARD OF THE DIGITAL
TION DIRECTSEQUENCE SPREAD AND /103+ MOD
UNIT &OR THE FORWARD LINK DIGITAL UNIT ENCODES
ULATED FOR TRANSMISSION !T THE BASE STATION
AND MODULATES THE INFORMATION SIGNAL THEN THE
THE DEMODULATION IS PERFORMED BY `NGER IN THE
SIGNAL IS UPCONVERTED TO THE )& BAND )T IS THEN
#$-! CHANNEL CARD
SENT TO 2& UNIT FOR UPCONVERSION TO 5(& FRE
DESPREAD USING TWO 0. SEQUENCES THEN ACCU
QUENCY BAND AND TRANSMITTED TO THE MOBILE STA
MULATED OVER THE 7ALSH CHIP PERIOD WHICH IS
TION 4HE "#0 CONTROLS THE OPERATION OF THE
EQUIVALENT TO 0. CHIPS 4HE ) AND 1 FAST
"43 SUCH AS CALL PROCESSING AND DEVICE INITIAL
(ADAMARD TRANSFORM &(4 IS COMPUTED ON THE
IZATION )T IS RESPONSIBLE FOR THE MANAGEMENT OF
ACCUMULATED ) AND 1 DATA BY CORRELATING THE
RESOURCES IN THE "43 SUCH AS FREQUENCY ASSIGN
DATA WITH POSSIBLE 7ALSH SEQUENCES 4HE
MENT CODE CHANNEL FRAME O_SET AND POWER AL
7ALSH SYMBOL THAT HAS THE LARGEST CORRELATION
4HE ) AND 1 DATA IS
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER  
 
 −   − 


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)
&IG "LOCK DIAGRAM OF THE BASE STATION DEMODULATOR
RESULT IS SELECTED AS THE DEMODULATED 7ALSH
SYMBOL
"EFORE DEMODULATION THE BASE STA
TION MUST ACQUIRE THE MOBILE STATION THROUGH
PREAMBLE SEARCHING 4HE $333 #$-! SYSTEM
WORKS ONLY WHEN THE CHIP TIMING OF THE RECEIVER
IS SYNCHRONIZED TO THAT OF THE TRANSMITTED SIG
NAL 4HE CODE SYNCHRONIZATION CONSISTS OF TWO
STEPS CODE ACQUISITION AND CODE TRACKING WHICH
ARE PERFORMED BY SEARCHER AND BY `NGER RESPEC
TIVELY &IGURE SHOWS THE BLOCK DIAGRAM OF THE
BASE STATION DEMODULATOR
" #ODE !CQUISITION AND 4RACKING
4HE PURPOSES OF THE REVERSE LINK CODE
SYNCHRONIZATION ARE TO ACQUIRE THE ACCESS
PREAMBLE IN THE ACCESS CHANNEL TO ACQUIRE
TRAbC PREAMBLE AND TO `ND THE MULTI
PATH PRO`LE IN THE TRAbC CHANNEL AND AC
CESS CHANNEL &ROM THE CODE ACQUISITION BY
THE SEARCHER NEW MOBILE STATION OR NEW PO
TENTIAL PATHS FOR DEMODULATION ARE ACQUIRED
WITH COARSE RESOLUTION SUCH AS A HALF CHIP
RESOLUTION &INE TIMING ALIGNMENT SUCH AS
ONE EIGHTH CHIP RESOLUTION IS OBTAINED FROM
THE CODE TRACKING IN THE PROCESS OF DEMOD
ULATION 4HE PATH DIVERSITY IS OBTAINED BY
IMPLEMENTING RAKE RECEIVER WITH MULTIPLE
DEMODULATORS 4HE SEARCHING RESULTS AND
`NGER INFORMATION SUCH AS LOCK STATUS CUR
RENT PATH BEING LOCKED AND SYMBOL ENERGY
ARE USED TO DETERMINE WHETHER A `NGER IS
ASSIGNED TO A NEW PATH OR NOT
)N THE BASE STATION THE UNCERTAINTY RE
GION FOR CODE ACQUISITION IS DEPENDENT ON
THE CELL SIZE )N THE CURRENT IMPLEMENTATION
THE MAXIMUM CELL SIZE IS LIMITED TO KM
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER AND THE DEMODULATOR CANNOT PROCESS SIGNAL
DELAYED MORE THAN 0. CHIPS EQUIV
ALENTLY REVERSE LINK 7ALSH SYMBOLS
4HEREFORE THE NUMBER OF TESTS THAT THE BASE
STATION PERFORMS FOR THE CODE ACQUISITION IS
r WITH HALF 0. CHIP RESOLUTION
7ITH SEARCHER CON`GURATION AS IN THE CUR
RENT IMPLEMENTATION EACH SEARCHER NEEDS TO
PERFORM TESTS !SSUMING THAT
THE INTEGRATION PERIOD FOR PERFORMING EACH
TEST IS 0. CHIPS IT TAKES MS r
0. CHIPS TO TEST ALL THE HYPOTHESES )N THE
HYPOTHESIS TESTING FOR THE CODE ACQUISITION
SOPHISTICATED SETTING OF DECISION THRESHOLD
IS REQUIRED TO OBTAIN REASONABLY LOW FALSE
ALARM PROBABILITY )N THE TRAbC MODE AF
TER DETECTING THE MOBILE STATIONS PREAMBLE
THE BASE STATION BEGINS TO TRANSMIT TRAbC
PACKET !FTER RECEIVING VALID FRAMES FROM
THE BASE STATION THE MOBILE STATION STOPS
TRANSMITTING PREAMBLE AND BEGINS TO TRANS
MIT TRAbC DATA )F THE DECISION THRESH
OLD IS SET TOO LOW THE BASE STATION EASILY
TAKES NOISE FOR SIGNAL IT THEN CANNOT GET
BACK TO THE MOBILE STATION PREAMBLE DETEC
TION STATE AND AS A RESULT THE CALL WILL BE
DROPPED 4O SATISFY THIS THRESHOLD SETTING
REQUIREMENT THE BASE STATION #$-! MO
DEM USES THE MAXIMUMLIKELIHOOD SEARCH
TECHNIQUE FOR INITIAL CODE ACQUISITION WITH
SINGLE `XED DWELL TIME DETECTOR ;=
4HE -(Z OF 0. CHIP RATE MAKES
IT POSSIBLE TO REALIZE SIMPLE DELAYLOCK LOOP
WITH COMPLETELY DIGITAL TECHNIQUE 4HE DIG
ITAL TECHNIQUE REMOVES THE ARM BALANCING
PROBLEM IN THE DELAYLOCK LOOP WHICH MAY
OCCUR WHEN IT IS IMPLEMENTED WITH ANALOG
TECHNIQUE %VERY MS POWER CONTROL
GROUP 0. CODE PHASE IS UPDATED BY THE
CODE TRACKING LOOP )N THE #$-! SYSTEM
THE MOBILE STATION TRANSMITS DATA IN BURST
MODE 4HEREFORE IN CERTAIN POWER CONTROL
GROUPS NO DATA ARE TRANSMITTED 4HIS CAN
CAUSE ERROR IN THE CODE TRACKING LOOP &OR
THIS REASON THE CODE TRACKING LOOP IS UP
DATED WITH THE NEW ERROR METRIC ONLY IF
SIGNAL IS PRESENT DURING THE POWER CONTROL
GROUP )N ADDITION THE CODE TRACKING LOOP
CAN BE SET IN THE WAY IT IS UPDATED IF THE
COMBINED 7ALSH SYMBOL IS THE SAME AS THE
DEMODULATED 7ALSH SYMBOL IN THE `NGER
# 2AKE 2ECEIVER
4HE RAKE RECEIVER IS IMPLEMENTED BY
COMBINING 7ALSH SYMBOLS FROM MULTIPLE `N
GERS FOR DEMODULATION 4HE 7ALSH SYM
BOL THAT HAS THE BIGGEST COMBINED CORRE
LATION RESULTS IS SELECTED AS THE DEMODU
LATED 7ALSH SYMBOL &OR SYMBOL COMBINING
ALL THE CORRELATION RESULTS OF THE RECEIVED
SIGNAL WITH POSSIBLE 7ALSH SYMBOLS ARE
REQUIRED HOWEVER THIS INCREASES COMPU
TATIONAL COMPLEXITY )N THE IMPLEMENTA
TION OF #$-! RAKE RECEIVER WITH BASE STA
TION !3)#S BY 1UALCOMM )NC ;= `NGERS
GIVE THE CHANNEL ELEMENT PROCESSOR ONLY THE
CORRELATION RESULTS WITH THE WINNING 7ALSH
SYMBOL )N THE CHANNEL ELEMENT PROCESSOR
THE WINNING SYMBOL WHOSE CORRELATION RESULT
IS GREATER THAN A THRESHOLD IS CONVERTED TO
BIT DATA "EFORE COMBINING THE SYMBOL
THE PROCESSOR GIVES WEIGHTS PROPERLY TO THE
$ONG7OOK ,EE ET AL
CORRELATION RESULTS 4HE BIT DATA AND THE
WEIGHT CORRESPONDING TO EACH BIT ARE CON
VERTED TO TUPLE VECTOR 4HEN THE PROCES
SOR SUMS THE SYMBOL VECTOR AND ARE INPUT TO
THE SERIAL 6ITERBI DECODER FOR SOFT DECISION
DECODING )F ALL THE WINNING SYMBOLS HAVING
MAGNITUDES GREATER THAN A THRESHOLD ARE THE
SAME THEN THE PERFORMANCE OF THIS METHOD
IS THE SAME AS THAT OF SOFT SYMBOL COMBINING
SYSTEM
"ASE 3TATION -ODEM !3)#S
4HE BASE STATION #$-! MODEM IS IM
PLEMENTED IN THE BASE STATION CHANNEL CARD
WHICH IS PRIMARILY RESPONSIBLE FOR PROCESS
ING CALLS WITHIN THE BASE STATION )N THE
TEST SYSTEM AND THE COMMERCIAL SYSTEM CUR
RENTLY BEING DEVELOPED THE BASE STATION
CHANNEL CARD WHICH IS RESPONSIBLE FOR TRANS
MITTING AND RECEIVING SIGNAL TO AND FROM
MOBILE STATIONS OVER THE AIR HAS BEEN IMPLE
MENTED WITH TWO KINDS OF #$-! !3)# PRO
VIDED BY 1UALCOMM )NC 4HE `RST GENERA
TION #$-! MODEM IS COMPRISED OF #$-!
!3)# SET WHICH CONSISTS OF FOUR BASE STA
TION DEMODULATORS A BASE STATION MODULA
TOR AND A SERIAL 6ITERBI DECODER )N 1UALCOMM )NC INTRODUCED THE SECOND GEN
ERATION BASE STATION #$-! !3)# WHICH IS
CALLED CELL SITE MODEM CHIP #3- WHERE
THE `RST GENERATION SIX CHIP SET IS INTE
GRATED 4HIS #3- MAKES THE STRUCTURE OF
#$-! MODEM AND ITS CONTROL SCHEME SIM
PLE !S A RESULT IT BECOMES POSSIBLE FOR ONE
MICROPROCESSOR TO CONTROL SEVERAL #$-!
%42) *OURNAL VOLUME NUMBER /CTOBER MODEMS OPERATING IN A DI_ERENT CHANNEL AP
PLICATION MODE AND IN FUTURE SYSTEM THE SIZE
OF DIGITAL SHELF WILL BE GREATLY REDUCED
! &IRST 'ENERATION #$-! !3)#
4HE `RST GENERATION #$-! MODEM IS
COMPOSED OF !3)#S OF KINDS THAT IS
FOUR DEMODULATORS A MODULATOR AND A SE
RIAL 6ITERBI DECODER 4HE DEMODULATOR CON
SISTS OF A PROCESSING BLOCK FRONT END IN
TERFACE MICROPROCESSOR INTERFACE AND CLOCK
GENERATOR 4HE PROCESSING BLOCK IS COM
PRISED OF ONE DEMODULATING `NGER AND TWO
SEARCHERS 4HE `NGER IS USED FOR DATA DE
MODULATION AND CODE TRACKING AND THE TWO
SEARCHERS ARE USED TO CONTINUOUSLY SCAN FOR
OTHER STRONG MULTIPATH SIGNALS 4HE FRONT
END INTERFACE SELECTS ONE OF SIX INCOMING
DATA STREAMS TO FEED TO THE `NGER OR TO
THE SEARCHERS 4HE INPUT TO THE `NGER AND
SEARCHERS ARE INDEPENDENT 4HE MICROPRO
CESSOR INTERFACE DELIVERS PROCESSED DATA TO
THE I FOR FURTHER DIGITAL SIGNAL PROCESSING
SUCH AS RAKE COMBINING AND `NGER ASSIGN
MENT TO A NEW PATH 4HE CLOCK GENERATOR
RECEIVES THE EXTERNAL CLOCK SIGNAL THEN GEN
ERATES AND DISTRIBUTES THE INTERNAL CLOCK SIG
NAL REQUIRED BY THE DEMODULATOR -ORE DE
TAILED OPERATION OF DEMODULATOR IS DESCRIBED
IN ;=
4HE INCOMING SIGNAL THROUGH EACH AN
TENNA IS DOWNCONVERTED TO BASEBAND AND
SAMPLED TO PRODUCE A SEQUENCE OF DIGITAL
DATA THAT IS AT TIMES THE 0. CHIP RATE
THIS IS CALLED SYSTEM CLOCK -(Z
AND IS IN O_SET TWOS COMPLEMENT FORMAT
%42) *OURNAL VOLUME NUMBER /CTOBER &OR A THREESECTORED BASE STATION DATA FROM
DI_ERENT SECTORS ARE FED TO THE DEMODULATOR
VIA DATA LINES 4HESE DATA LINES ARE DI
VIDED INTO THREE GROUPS OF EIGHT LINES %ACH
GROUP REPRESENTS DATA FROM A SPECI`C SECTOR
AND IS SPLIT INTO CHANNEL ) AND 1 4HE DATA
FROM TWO ANTENNAS OF THE SAME SECTOR ARE
TIME MULTIPLEXED ONTO THESE DATA LINES 4HE
SYNCHRONOUS INPUT DATA LINES TO THE DEMOD
ULATOR HAVE TRANSITION STREAMS AT THE FALLING
EDGE OF THE SYSTEM CLOCK AND ARE DEMULI
PLEXED FOR TWO ANTENNAS 4HE FRONT END IN
TERFACE ALSO CONTROLS THE SOURCE FOR THE `NGER
AND THE TWO SEARCHERS ACCORDING TO THE CON
TROL OF THE I#! 3INCE THE CURRENT VERSION
OF DEMODULATOR HAS SOME BUGS IN LOCK DETEC
TOR AND CODE TRACKING LOOP OPERATION THOSE
ARE PERFORMED BY SOFTWARE LOADED ON THE
I#! &URTHERMORE SINCE EACH DEMODU
LATOR GIVES THE I#! ONLY THE MAGNITUDE
FOR THE WINNING SYMBOL THE I#! CANNOT
PERFORM SOFT SYMBOL COMBINING
4HE MODULATOR PERFORMS CONVOLUTIONAL
ENCODING TO THE FORWARD LINK INFORMATION
DATA INTERLEAVING PULSE SHAPING 7ALSH
COVERING TO ORTHOGONALIZE THE FORWARD CHAN
NELS AND SYMBOL SPREADING )T ALSO PER
FORMS DEINTERLEAVING TO THE RECEIVED DATA
AND FEEDING THE DEINTERLEAVED DATA TO SERIAL
6ITERBI DECODER FOR THE PROCESSING OF REVERSE
LINK DATA 4HE MODULATOR HAS TWO TRANSMIT
SECTIONS &OR EACH SECTION THE TRANSMITTED
SYMBOLS ARE COVERED WITH DI_ERENT 7ALSH
SEQUENCE AND SPREAD BY DI_ERENT PILOT 0.
SEQUENCE WITH DI_ERENT GAIN 4HIS STRUC
TURE ENABLES SOFTER HANDO_ WITHIN A CELL
$ONG7OOK ,EE ET AL
IE WITHIN A CHANNEL CARD 3INCE EACH SEC
TION CAN TRANSMIT PILOT CHANNEL SIGNAL ONLY
A MODULATOR CAN TRANSMIT PILOT SIGNAL TO
GETHER WITH SYNC CHANNEL DATA OR PAGING
CHANNEL DATA -ORE DETAILED OPERATION OF
MODULATOR IS DESCRIBED IN ;=
4HE 6ITERBI DECODER USES THE SERIAL
6ITERBI DECODING 36$ ALGORITHM TO DE
CODE A SYNCHRONIZED AND QUANTIZED CODE
SYMBOL STREAM 4HIS CHIP IS USED IN BOTH
BASE STATION AND MOBILE STATION WITH PROP
ERLY SETTING THE CON`GURATION )T INCLUDES AN
INPUT BU_ER THAT ALLOWS DATA TO BE RECEIVED
VIA A SERIAL INPUT )T PROVIDES AN INTERRUPT
SIGNAL FOR THE MICROPROCESSOR AND AN OUTPUT
BU_ER FOR THE DECODED DATA IN ORDER TO ISO
LATE THE MICROPROCESSOR FROM SYSTEM FRAME
TIMING 4HE 36$ ALSO PRODUCES STATUS IN
FORMATION SUCH AS SYMBOL ERROR COUNT #2#
CHECK RESULT AND THE QUALITY BIT FOR THE BEST
STATE METRIC 4HE 36$ IS NOT GIVEN THE CODE
SYMBOL RATE WHEN OPERATING IN SOME CHAN
NEL MODE )T TRIES FOUR POSSIBLE RATES FULL
HALF QUARTER AND EIGHTH RATES AND COM
PUTES THE PROCESSING STATUS DATA MENTIONED
ABOVE FOR EACH RATE TO ASSIST THE MICROPRO
CESSOR TO DETERMINE WHAT THE MOST PROBABLE
DATA RATE IS )T MAY ALSO SERVE AS AN INDI
CATOR TO DECIDE WHETHER OR NOT THE DECODED
FRAME IS VALID 4HE DECODED OUTPUT DATA
ARE REENCODED AND COMPARED WITH THE IN
PUT CODE SYMBOL TO DETERMINE THE SYMBOL
ERROR COUNT 4HE DECODED DATA FOR THE FOUR
POSSIBLE DATA RATES ARE STORED IN THE OUT
PUT BU_ER AND AFTER DETERMINING THE MOST
PROBABLE DATA RATE MICROPROCESSOR CAN READ
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER $
-**
*+,%
.&/$
&,$/$,*+
0&$,*+
1&$*2*
.&/$
&,$/$,*+
0&$,*+
1&$*2*
,
*+
3
,
456
,5.7
,
&IG /PERATIONS IN THE !3)# FOR THE FORWARD LINK
THE DECODED DATA FOR THAT DATA RATE BY WRIT
ING THE PREDE`NED OUTPUT BU_ER ADDRESS FOR
THE MOST PROBABLE DATA RATE INTO A REGIS
TER -ORE DETAILED INFORMATION ON THE SERIAL
6ITERBI DECODER IS IN ;=
$ATA aOWS AND OPERATIONS IN THE #$-!
!3)#S FOR THE FORWARD LINK AND REVERSE LINK
ARE SHOWN IN &IG AND &IG RESPECTIVELY
" 3ECOND 'ENERATION #$-! !3)#
)N 1UALCOMM )NC INTRODUCED A
NEW #$-! !3)# CALLED #3- 4HIS SINGLE
CHIP CAN REPLACE THE PREVIOUSLY DESCRIBED
SIX `RST GENERATION #$-! !3)#S 3INCE
IT SUPPORTS MOST OF LOW LEVEL PHYSICAL LAYER
TASKS SUCH AS LOCK DETECTION SYMBOLBASED
DEMODULATION O_SETBASED SEARCHING AND
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER 08
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&IG (IGH LEVEL BLOCK DIAGRAM OF #3- ;=
SORTING THE SEARCHING RESULTS A MICROPRO
ING IS DONE IN A CHIP SOFT COMBINING CAN
CESSOR CAN CONTROL SEVERAL #$-! MODEMS
BE PERFORMED ON THE OPTIMAL BASIS )T CAN
SIMULTANEOUSLY !ND SINCE SYMBOL COMBIN
PERFORM THREEWAY SOFTER HANDO_ SINCE ONE
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER %
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&IG !RCHITECTURE OF THE "43
TRANSMIT SECTION IS ADDED TO THE MODULA
TOR SECTION &IGURE IS A BLOCK DIAGRAM OF
#3- &OR MORE DETAILS REFER TO ;=
))) 3934%- !2#()4%#452%
!.$ /0%2!4)/.3
!RCHITECTURE OF "43
4HE "43 IS COMPOSED OF 2& UNIT DIG
ITAL UNIT "). AND "#0 4HE ARCHITECTURE
OF THE "43 AND THEIR INTERCONNECTION ARE
SHOWN IN &IG 4HE ANALOG COMMON CARD
!## RECEIVES THREE TIMING SIGNALS SYS
TEM CLOCK -(Z A PULSE EVERY
OTHER SECOND %6%. 3%# CLOCK AND A -(Z REFERENCE TO BE USED FOR SYNTHESIZ
ING THE -(Z IN REVERSE LINK 103+
DEMODULATION 4HE !## DISTRIBUTES SYS
TEM CLOCK AND %6%. 3%# TO THE REST OF
THE DIGITAL SHELF )N THE FORWARD LINK THE
!## COMBINES THE INCOMING BASEBAND SIG
NALS FROM THE CHANNEL CARDS WITHIN A DIGI
TAL SHELF 4HESE SIGNALS START FROM THE OUT
PUT OF THE MODULATOR !3)# THEN THEY ARE
PASSED THROUGH A DIGITAL COMBINER 4HE
) AND 1 OUTPUTS ARE CONVERTED TO ANALOG
THROUGH A SET OF DIGITALTOANALOG CONVERT
ERS AND `LTERS 4HE SINGLE ENDED ANALOG
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER SIGNALS ARE CONVERTED INTO DI_ERENTIAL BEFORE
GOING TO BACKPLANE 4HE !## RECEIVES THESE
SUMMED SIGNAL DI_ERENTIALLY AND TRANSMITS
THEM TO THE SECTOR INTERFACE CARD 3)#
TO OTHER DEVICES IN THE "43 DIGITAL SHELF
)N THE REVERSE LINK SIGNALS FROM THE TWO
ANTENNAS PASS THROUGH THE 2& UNIT AND EN
TER THE !## 4HE SIGNAL IS PASSED THROUGH
A PASSIVE LOW PASS `LTER AND AN !'# LOOP
THEN CONVERTED TO DIGITAL SIGNAL 4HE OUTPUT
OF FOUR ANALOGTODIGITAL CONVERTERS !$#S
WHICH ARE BIT EACH AT -(Z IS
PASSED THROUGH A -58 WITH AN OUTPUT OF BITS AT -(Z
MONITORING THE STATUS OF THE 3)# FOR THE
4HE MAIN FUNCTION OF THE 3)# IS TO COM
BINE THE BASEBAND FORWARD LINK SIGNALS AND
TO UPCONVERT THEM TO )& FREQUENCY )N THE
FORWARD LINK THE 3)# RECEIVES THE COMBINED
BASEBAND TRANSMIT SIGNALS FROM THE !##S
COMBINES AND AMPLI`ES THEM BY A NOMI
NAL GAIN ABOUT D"M 4HIS SIGNAL IS THEN
PASSED THROUGH A LOW PASS `LTER ,0& WITH
BANDWIDTH OF K(Z !FTER THESE SIGNALS
ARE PASSED THROUGH TWO MIXERS WITH THE )&
FREQUENCY -(Z AND DEGREES
THEY ARE COMBINED AND `LTERED VIA A BAND
PASS `LTER
4HE TIME AND FREQUENCY REFERENCE CARD
4&# RECEIVES ONE PULSE PER SECOND 003 AND THE -(Z REFERENCE CLOCK FROM
THE '03 RECEIVER AND GENERATES THE -(Z SYSTEM CLOCK 393 #,+ SYNCHRO
NIZED TO THE -(Z CLOCK BY 0,, BU_ERED
-(Z REFERENCE CLOCK AND THE ONE PULSE
PER TWO SECOND %6%. 3%# TIME REFERENCE
SIGNAL SYNCHRONIZED TO 003 SIGNAL 4HE
4&# DISTRIBUTES THESE THREE TIMING SIGNALS
4HE 4&# TRANSMITS AND RECEIVES CONTROL
MESSAGES TO AND FROM THE "#0 THROUGH THE
"). AND IT INITIALIZES THE 3)# AND KEEPS
FAULT DETECTION PURPOSE 4WO 4&# BOARDS
ARE PLACED IN THE DIGITAL SHELF TO PROVIDE THE
REDUNDANCY /NE OF THE 4&# BOARDS ACTS IN
THE ACTIVE MODE AND THE OTHER BOARD STAYS
IN THE STANDBY MODE /N DETECTION OF FAIL
URE IN THE ACTIVE 4&# THE OUTPUT IS CUT
O_ AND THE CONTROL IS HANDED OVER TO THE
STANDBY 4&#
4HE "#0 CONTROLS AND MONITORS THE
OVERALL OPERATIONS OF THE "43 PERFORMS
"43 HARDWARE AND SOFTWARE CON`GURATION
AND MANAGES RESOURCE ALLOCATION )N THE
POWERUP STATE THE "#0 INITIALIZES THE
SUBORDINATE "43 DEVICES DOWNLOADS EXE
CUTABLE CODES AND CON`GURATION DATA TO THE
"43 DEVICES ACCORDING TO THE CELL CON`GU
RATION DATA `LE 7HEN A CALL IS ATTEMPTED
THE "#0 ALLOCATES RESOURCES SUCH AS FRE
QUENCY ASSIGNMENT CODE CHANNEL FRAME O_
SET AND TRANSMIT POWER IN THE WAY TO MAXI
MIZE THE SUCCESSFUL CALL COMPLETION RATE AND
THE RESOURCE AVAILABILITY )T ALSO DYNAMI
CALLY CHANGES PILOT POWER AND CELL 2& TOTAL
TRANSMIT POWER TO MAINTAIN THE TRAbC LOAD
BALANCE BETWEEN CELLS 4HE "#0 MONITORS
THE OPERATIONS OF THE "43 DEVICES AND RE
PORTS THE STATUS TO THE "3- IN CASE FAULTS
ARE DETECTED )T IS ALSO DUPLICATED TO PRE
VENT CATASTROPHIC SHUTDOWN OF THE CELL
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER !"
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&IG #HANNEL CARD USING BASE STATION !3)# CHIP SET
#HANNEL #ARD
4HE CHANNEL CARD CONSISTS OF CHANNEL EL
EMENTS CHANNEL CARD CONTROLLER AND INTER
FACES TO PACKET SWITCHED NETWORK
%ACH
CHANNEL ELEMENT CAN CARRY OUT REQUIRED
#$-! SIGNAL PROCESSING OPERATIONS FOR THE
FORWARD CHANNELS AND THE REVERSE CHANNELS
4HE CHANNEL CARD IS DESIGNED TO BE OPERATED
ON THE SAME HARDWARE REGARDLESS OF CHAN
NEL TYPES 4HE CHANNEL ELEMENT FUNCTIONS
AS A TRANSMITTER FOR THE PILOT CHANNEL THE
SYNC CHANNEL THE PAGING CHANNEL AND THE
TRAbC CHANNEL ON THE FORWARD LINK AND AS
%42) *OURNAL VOLUME NUMBER /CTOBER A RECEIVER FOR THE ACCESS CHANNEL AND THE
TRAbC CHANNEL ON THE REVERSE LINK BY RUN
NING DI_ERENT SOFTWARE ON THE SAME HARD
WARE )N THE "43 INITIALIZATION PROCESS THE
"#0 DOWNLOADS THE CHANNEL ELEMENT SOFT
WARE AND CON`GURATION PARAMETERS WHICH
DETERMINE THE PERSONALITY OF THE CHANNEL EL
EMENT -OST OF #$-! SIGNAL PROCESSING
OPERATIONS ARE CARRIED OUT IN THE !3)#S
7E HAVE IMPLEMENTED TWO VERSIONS OF CHAN
NEL CARDS USING TWO KINDS OF #$-! !3)#S
SUPPLIED BY 1UALCOMM )NC
&IGURE SHOWS THE BLOCK DIAGRAM OF
CHANNEL CARD USING 1UALCOMMS `RST GEN
ERATION CHIP SET 4HE CHANNEL CARD CON
SISTS OF TWO CHANNEL ELEMENTS AND A COM
MON SECTION %ACH CHANNEL ELEMENT CON
SISTS OF DEMODULATORS ONE MODULATOR ONE
SERIAL 6ITERBI DECODER AND A CHANNEL ELE
MENT PROCESSOR 4HE COMMON SECTION CON
SISTS OF A CHANNEL CARD CONTROLLER A DIGITAL
COMBINER AND DIGITALTOANALOG CONVERTERS
$!#S 4HE CHANNEL CARD CONTROLLER ROUTES
TRAbC AND CONTROL DATA BETWEEN CHANNEL EL
EMENTS AND BASE STATION NETWORK ELEMENTS
SUCH AS TRANSCODING AND SELECTION BLOCK
43" "#0 LOGGING DEVICES AND DIAGNOS
TIC MONITOR /N THE FORWARD LINK THE CHAN
NEL ELEMENT RECEIVES TRAbC AND CONTROL DATA
PACKETS FROM 43" DISASSEMBLES THE PACK
ETS AND SEPARATES OUT THE CONTROL INFORMA
TION )T THEN PACKETIZES THE TRAbC DATA
AND SYNCHRONIZES IT TO THE OVERTHEAIR TIM
ING 4HE MODULATOR !3)# CONVOLUTIONALLY
ENCODES INTERLEAVES SCRAMBLES THE CODED
SYMBOLS AND COVERS THE DATA WITH THE OR
THOGONAL 7ALSH SEQUENCE THEN SPREADS IT
$ONG7OOK ,EE ET AL
WITH )1 0. SEQUENCES 4HE )1 DIGITAL
WAVEFORMS FROM TWO CHANNEL ELEMENTS ARE
COMBINED AND CONVERTED INTO BASEBAND ANA
LOG WAVEFORMS 4HE ANALOG BASEBAND SIG
NALS FROM CHANNEL CARDS ARE COMBINED AND
UPCONVERTED TO THE )& FREQUENCY BAND IN THE
!## AND 3)#
/N THE REVERSE LINK THE CHANNEL ELEMENT
PROCESSOR ASSIGNS A SECTOR AND AN ANTENNA
TO EACH DEMODULATOR !3)# FOR DEMODULA
TION 4HE RECEIVED DIGITAL DATA IS INPUT
TO THE CHANNEL CARD FROM !## THROUGH A
BIT BUS RUNNING AT -(Z WHICH
IS TIMES THE CHIP RATE 4HIS PROVIDES
FOURBIT ) AND 1 SAMPLES FROM SIX ANTEN
NAS AT A -(Z RATE PER ANTENNA 4HE
CHANNEL ELEMENT PROCESSOR COMBINES THE DE
MODULATED SYMBOLS FROM ALL THE DEMODULA
TOR !3)#S TO TAKE ADVANTAGE OF TIME AND
SPATIAL DIVERSITY 4HE COMBINED DATA IS
DEINTERLEAVED AND DECODED IN THE MODULA
TOR !3)# AND SERIAL 6ITERBI DECODER RESPEC
TIVELY 4HE DECODED VOICE DATA ARE THEN
PACKETIZED AND SENT TO 43" THROUGH THE
PACKET SWITCHED INTERCONNECTION NETWORK
4HE CHANNEL CARD USING #3- !3)#
1UALCOMMS SECOND GENERATION BASE STATION
!3)# IS SHOWN IN &IG 3IX `RST GENERA
TION BASE STATION !3)# CHIPS WHICH ARE DEMODULATORS ONE MODULATOR AND ONE SE
RIAL 6ITERBI DECODER ARE INTEGRATED INTO A
SINGLE #3- CHIP )N ADDITION TO INTEGRA
TION DENSITY MOST OF LOW LEVEL PHYSICAL LAYER
PROCESSING SUCH AS LOCK DETECTION SYMBOL
BASED DEMODULATION O_SETBASED SEARCHING
AND SORTING THE SEARCHING RESULTS WHICH IS
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER 4
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&IG #HANNEL CARD USING #3- !3)#S
CARRIED OUT BY THE CHANNEL ELEMENT PROCES
SOR FOR THE `RST GENERATION CHIP SET IS PER
FORMED INSIDE THE #3- CHIP 4HIS MAKES
CHANNEL CARD ARCHITECTURE OF MANY #3CHIPS AND A SINGLE CONTROL PROCESSOR "E
CAUSE OF LESS COMPUTATIONAL AND )/ BUR
DEN THE CONTROL PROCESSOR CAN CONTROL MANY
#$-! MODEMS SIMULTANEOUSLY )N THE
#3- THE SYMBOL COMBINER IS IMPLEMENTED
INSIDE THE CHIP 4HIS MAKES IT POSSIBLE FOR
EACH `NGER TO GIVE THE SYMBOL COMBINER ALL
THE CORRELATION RESULTS OF THE RECEIVED SIGNAL
%42) *OURNAL VOLUME NUMBER /CTOBER $ONG7OOK ,EE ET AL
WITH POSSIBLE 7ALSH SYMBOLS 4HE CHAN
NEL ELEMENT PROCESSOR GIVES THE #3- ONLY
A THRESHOLD BY WHICH THE #3- DETERMINES
WHICH `NGER SHOULD BE ENABLED FOR COMBIN
ING 4HE SYMBOL COMBINER COMBINES THE
CORRELATION RESULTS FOR 7ALSH SYMBOL OUT
PUT FROM EACH ENABLED `NGER 4HE 7ALSH
SYMBOL THAT HAS THE BIGGEST COMBINED COR
RELATION VALUE IS SELECTED AS A DEMODULATED
7ALSH SYMBOL 4HE CHANNEL CARD IS DE
SIGNED TO SUPPORT CHANNEL ELEMENTS 4HE
!3)#S ARE CONTROLLED BY A SINGLE PROCESSOR
)T HAS BEEN SHOWN THAT THE )NTEL I PROCES
SOR HAS ENOUGH COMPUTING POWER TO SUPPORT
MORE THAN CHANNEL ELEMENTS
&IGURE SHOWS THE PICTURE OF THE IMPLE
MENTED #$-! CHANNEL CARD USING THE `RST
GENERATION !3)# SETS AND THE SECOND GENER
ATION !3)#S
0OWER #ONTROL IN THE "43
#$-! IS AN INTERFERENCELIMITED SYSTEM
IN THE SENSE THAT THE SYSTEM CAPACITY IS
CLOSELY RELATED TO THE AMOUNT OF INTERFER
ENCE THE SYSTEM RECEIVES ,ARGE CAPACITY
IS ONE OF ADVANTAGES THAT #$-! SYSTEM
O_ERS (OWEVER THE MAXIMUM CAPACITY IS
ACHIEVED WHEN THE PERFECT POWER CONTROL IS
PERFORMED 4HIS IS BECAUSE THE AMOUNT OF
INTERFERENCE IS DETERMINED BY THE RECEIVED
SIGNAL LEVEL FROM EACH USER 4HE SYSTEM CA
PACITY IS MAXIMIZED IF THE TRANSMIT POWER
OF EACH MOBILE STATION IS CONTROLLED IN THE
WAY THAT THE CELL RECEIVED POWER IS MINI
MUM AS LONG AS THE BASE STATION CAN COR
RECTLY DEMODULATE THE RECEIVER SIGNALS 4HE
PURPOSE OF THE REVERSE LINK POWER CONTROL IS
&IG 4HE PICTURE OF THE IMPLEMENTED #$-! CHAN
NEL CARDS
TO COPE WITH THE <NEAREND FAREND PROB
LEM 7HEN SOME MOBILE STATIONS ARE CLOSE
TO THE BASE STATION THEY HAVE STRONGER SIG
NALS THAN MOBILE STATIONS FAR FROM THE BASE
STATION AND MAY CAUSE UNNECESSARY INTER
FERENCE ON THE REVERSE LINK UNLESS THEY ARE
CONTROLLED ! COMBINATION OF OPEN LOOP AND
CLOSED LOOP POWER CONTROL IS USED ON THE RE
VERSE LINK TO COMMAND THE MOBILE STATION
$ONG7OOK ,EE ET AL
TO ADJUST THE TRANSMIT POWER 4HE MOBILE
STATION MEASURES THE RECEIVED POWER AS A
PART OF THE OPEN LOOP POWER CONTROL )N
THE CLOSED LOOP POWER CONTROL MODE THE
BASE STATION MEASURES THE RECEIVED POWER
AND MAKES DECISION WHETHER IT COMMANDS
THE MOBILE UNIT TO INCREASE OR TO DECREASE
THE TRANSMIT POWER 4HE OBJECTIVE OF THE
FORWARD LOOP POWER CONTROL IS TO KEEP THE
3.2 AT THE MOBILE STATION ALMOST CONSTANT
-OBILE STATIONS LOCATED NEAR CELL BOUNDARY
WILL REQUIRE MORE POWER THAN MOBILES CLOSE
TO THE CENTER OF THE CELL BECAUSE MOBILES
FAR FROM THE BASE STATION HAVE MORE TRANS
MISSION LOSS AND MORE INTERFERENCE FROM AD
JACENT CELLS THIS IS KNOWN AS THE <CORNER
PROBLEM 4HE REVERSE LINK AND THE FORWARD
LINK POWER CONTROL IN THE LANDSIDE NETWORK
IS PERFORMED IN THE "43 AND "3# 4HE OP
ERATIONS FOR THE POWER CONTROL PERFORMED IN
THE "43 ARE DESCRIBED BELOW
! 2EVERSE ,INK 0OWER #ONTROL
4HE MOBILE STATION MEASURES THE RE
CEIVED SIGNAL POWER TO ESTIMATE THE PATH
LOSS FROM THE BASE STATION TO THE MOBILE
UNIT -OBILERECEIVED SIGNAL STRENGTH AS A
MOBILE DRIVES AWAY FROM THE BASE STATION
IS TYPICALLY REPRESENTED BY LONGTERM FADING
LOGNORMAL FADING AND SHORTTERM FADING
2AYLEIGH FADING 4HE MEASURED MOBILE
RECEIVED POWER IS USED TO ESTIMATE THE PATH
LOSS AND TO ADAPT TO A SUDDEN DEGRADATION
OR IMPROVEMENT IN THE CHANNEL 0ROMPT AD
JUSTMENT TO THIS SUDDEN CHANGE IN THE CHAN
NEL IS IMPORTANT BECAUSE SLOW RESPONSE TO
%42) *OURNAL VOLUME NUMBER /CTOBER THE CHANNEL IMPROVEMENT WILL CAUSE INCREASE
OF RECEIVED SIGNAL POWER AT THE BASE STA
TION HENCE ADDITIONAL INTERFERENCE TO ALL THE
OTHER SIGNALS 4HE ESTIMATE OF REVERSE LINK
PATH LOSS IS USED TO ADJUST TRANSMIT POWER
AT THE MOBILE STATION )F THE RECEIVED SIG
NAL LEVEL IS HIGH THE MOBILE STATION ADJUSTS
THE POWER LEVEL DOWNWARDS 3TRONG RECEIVED
SIGNAL INDICATES THAT THE MOBILE IS LOCATED
NEAR THE BASE STATION OR THE PATH BETWEEN
MOBILE AND BASE STATION IS UNUSUALLY GOOD
)N THIS CASE MOBILE NEEDS LESS POWER TO MAKE
THE SIGNAL RECEIVED AT THE BASE STATION KEEP
A NOMINAL 3.2 4HIS OPEN LOOP POWER CON
TROL MECHANISM DETERMINES THE TRANSMIT RE
VERSE LINK POWER BASED ON THE RECEIVED SIG
NAL STRENGTH IN THE FORWARD LINK (OWEVER
THE #$-! SYSTEM USES THE FREQUENCY DIVI
SION DUPLEX &$$ IN OTHER WORDS THE FOR
WARD LINK AND THE REVERSE LINK HAVE DI_ERENT
FREQUENCY BANDS 4HIS IMPLIES THAT THE IN
STANTANEOUS PATH LOSS ON THE FORWARD LINK IS
DI_ERENT FROM THAT ON THE REVERSE LINK 4HE
NECESSITY OF CLOSED LOOP POWER CONTROL COMES
FROM THIS INDEPENDENT FAST FADING 4O AC
COUNT FOR THIS UNCORRELATED FADING ON THE
FORWARD AND THE REVERSE LINKS THE MOBILE
STATION TRANSMIT POWER IS ALSO CONTROLLED
BY A COMMAND FROM THE BASE STATION !T
THE BASE STATION EACH DEMODULATOR MEA
SURES THE RECEIVED SIGNAL STRENGTH AND ES
TIMATES %B.O BASED ON THE MEASUREMENTS
)F THE MEASURED %B .O IS GREATER THAN THE
DESIRED VALUE %B .O SET POINT THE BASE STA
TION SENDS THE COMMAND TO THE MOBILE TO
ADJUST THE TRANSMIT POWER DOWNWARDS
%42) *OURNAL VOLUME NUMBER /CTOBER 4HE CHANNEL ELEMENT RECEIVES THE THRESH
OLD VALUE %B .O SET POINT FROM THE 43" EV
ERY MS 4HIS THRESHOLD VALUE IS USED TO
SEND THE POWER CONTROL COMMAND TO THE MO
BILE STATION 4HE CHANNEL ELEMENT COMPUTES
THE RECEIVED %B .O FROM THE MEASURED EN
ERGY OF THE LOCKED `NGERS EVERY POWER CON
TROL GROUP MS AND THEN IT COMPARES
THE MEASURED %B .O WITH %B .O SET POINT 0OWER CONTROL COMMANDS ARE SENT TO THE
MOBILE STATION THROUGH THE POWER CONTROL
SUBCHANNEL 4HE POWER CONTROL BIT IS NOT
CODED WHEN IT IS SENT TO THE MOBILE 4HE
COMMAND BIT PUNCTURES THE CODED SYMBOLS
IN THE RANDOMIZED POSITION 4HIS POWER
CONTROL BIT PUNCTURING IS PERFORMED IN THE
MODULATOR !3)#
4HE REVERSE LINK POWER CONTROL ALGORITHM
IN THE NETWORK CONSISTS OF AN OUTER LOOP AND
AN INNER LOOP 4HE INNER LOOP ALGORITHM IN
TENDS TO MAINTAIN THE DESIRED REVERSE LINK
SIGNAL TO NOISE RATIO WHICH IS PERFORMED IN
THE CHANNEL CARD OF THE "43 4HE OUTER LOOP
ALGORITHM ADJUSTS THE DESIRED REVERSE LINK
SIGNAL TO NOISE RATIO BASED ON THE PERFOR
MANCE OF THE REVERSE LINK )N OTHER WORDS
THE OUTER LOOP POWER CONTROL IS TO CHANGE
%B.O SET POINT IN ORDER TO MAINTAIN CERTAIN
PERFORMANCE LIKE &%2 4HE 43" MEASURES
THE &%2 FROM THE TRAbC PACKETS RECEIVED
FROM THE "43 AND COMPARES IT WITH THE DE
SIRED &%2 )T DECREASES THE %B .O SET POINT
IF THE MEASURED &%2 IS LESS THAN THE DESIRED
&%2 AND THEN INCREASES THE %B .O SET POINT
IF THE RATE OF THE BAD FRAMES IS GETTING
LARGER
$ONG7OOK ,EE ET AL
" &ORWARD ,OOP 0OWER #ONTROL
!SSISTED BY THE MOBILE STATION THE BASE
STATION ADJUSTS THE AMOUNT OF POWER ALLO
CATED TO EACH TRAbC CHANNEL SO THAT THE
3.2 AT EACH MOBILE IS ALMOST CONSTANT
4O EACH CHANNEL ELEMENT BIT OF DIGITAL
GAIN IS ASSIGNED AND THE TRANSMIT POWER
IS PROPORTIONAL TO THE SQUARE OF THE DIGITAL
GAIN !S IN THE REVERSE LINK POWER CONTROL
MECHANISM THE FORWARD LOOP POWER CONTROL
MAY CONSIST OF AN OPEN LOOP CONTROL AND A
CLOSED LOOP CONTROL )N THE OPEN LOOP CON
TROL THE BASE STATION ESTIMATES THE FORWARD
LINK TRANSMISSION LOSS BASED ON THE MEA
SUREMENTS OF RECEIVED SIGNAL STRENGTH FROM
THE MOBILE IN THE ACCESS PROCEDURE THEN
THE BASE STATION ASSIGNS THE INITIAL DIGITAL
GAIN FOR EACH TRAbC CHANNEL ELEMENT )N
THE CLOSED LOOP CONTROL THE BASE STATION AD
JUSTS THE DIGITAL GAIN DYNAMICALLY IN COOP
ERATION WITH THE MOBILE 4YPICALLY THE BASE
STATION CONTINUOUSLY LOWER THE DIGITAL GAIN
UNTIL IT RECEIVES ANY COMPLAINT FROM THE MO
BILE 4HE MOBILE STATION MONITORS THE FRAME
QUALITY OF THE FORWARD TRAbC CHANNEL 7HEN
THE BASE STATION TRANSMITS SIGNAL WITH TOO
LOW POWER THE &%2 AT THE MOBILE INCREASES
4HE NUMBER OF BAD FRAME COUNT IS REPORTED
TO THE BASE STATION PERIODICALLY AND ALSO AT
A MOMENT WHEN THE COUNT OF BAD FRAME EX
CEEDS CERTAIN THRESHOLD )F THE BASE STATION
RECOGNIZES THAT THE FORWARD &%2 OR EQUIV
ALENTLY THE NUMBER OF BAD FRAMES EXCEEDS
SOME LEVEL IT INCREASES THE TRANSMIT POWER
BY ASSIGNING LARGER DIGITAL GAIN
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER )6 "!3% 34!4)/. 42!.3#%)6%2
35"3934% 2EVERSE 0ATH 5NITS
! 2X &RONT %ND 5NIT
4HE 2X &RONT %ND 5NIT 2X&5 PRO
VIDES A SIGNAL PATH FOR REVERSE LINK BETWEEN
THE 2X ANTENNA AND THE DISTRIBUTION SHELF
UNIT $)35 -AIN FUNCTIONS OF THE 2X&5
ARE REVERSE SIGNAL `LTERING AND SAMPLING )T
IS BASICALLY DESIGNED FOR FREQUENCY ASSIGN
MENTS &!S AND IS EXPANDABLE TO SUPPORT
UP TO &!S )T HAS TWO BLOCKS PER SECTOR
FOR SPACE DIVERSITY 7ITH SECTOR SYSTEM
CON`GURATION TOTALLY BLOCKS ARE USED FOR
ONE 2X&5 %ACH BLOCK OF 2X&5 SHOWN IN
&IG IS COMPOSED OF DIRECTIONAL COUPLER
2X BANDPASS `LTER ,.! ATTENUATOR AND
SPLITTER
"
#!
PATH LOSS 4HE 2X `LTER PROVIDES THE REJEC
TION OF SIGNALS WHICH ARE OUT OF CELLULAR -(Z BAND OR ALLOCATED SERVICE BAND )T
IS TYPICALLY A CAVITY TYPE HAVING LOW INSER
TION LOSS AND SPECIALLY GOOD SELECTIVITY 4HE
,.! IS A LOW NOISE AND HIGH DYNAMIC RANGE
AMPLI`ER FOR AMPLI`CATION OF THE RECEIVED
SIGNAL ! BALANCED TYPE CON`GURATION IS
DESIRABLE BECAUSE OF THE SOFT FAILURE MODE
4HE ATTENUATOR IS USED FOR GAIN MATCHING
TO DESIRED LEVEL AND THE SPLITTER PRO
VIDES TEST PORT FOR 2X&5 BLOCK ON SYSTEM
OPERATION WITHOUT DISTURBANCE 4HE CONTROL
SIGNAL FROM THE ,.! IS INTERFACED WITH THE
2&# AND USED FOR MONITORING WHETHER THE
,.! IS FAULT OR NOT
4HE LEVELS OF EACH DEVICE IN THE 2X&5
ARE DETERMINED TO MATCH SIGNAL INPUT LEVEL
CONDITION 'AINiD" .&D" TO
DOWNCONVERTER UNIT FOLLOWING THE $)35 )N
THE $)35 THE DIVIDER IS USED FOR SIGNAL DIS
TRIBUTION TO EACH DOWNCONVERTER UNIT MAX
%! INCLUDING REDUNDANCY 4HE DIVIDING
LOSS IN THE $)35 SHOULD BE CONSIDERED IN THE
DESIGN OF THE 2X&5
" 2ECEIVER #ARD
&IG /NE BLOCK STRUCTURE OF THE 2X&5
4HE DIRECTIONAL COUPLER IS USED FOR INJECT
ING TEST SIGNAL ON THE RECEIVE PATH 4HE LEVEL
OF COUPLING OF THE TEST SIGNAL MUST MATCH 4X
FRONT END UNIT 4X&5 IN ORDER TO PROPERLY
SIMULATE EQUAL FORWARD AND REVERSE SIGNAL
4HE RECEIVER CARD PROVIDES THE SIGNAL
PATH FROM THE 2X&5 TO THE $)35 )T PER
FORMS THE FOLLOWING FUNCTIONS
{ $OWNCONVERSION FROM 5(& TO AN )& OF
-(Z
{ #ELL BLOSSOMING WILTING AND BREATHING
THROUGH CONTROLLABLE NOISE `GURE DEGRA
DATION UNDER THE CONTROL OF 2&#
{ 2ECEIVED SIGNAL STRENGTH INDICATOR 233)
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER $
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&IG "LOCK DIAGRAM OF THE RECEIVER CARD
4HE RECEIVER CARD SHOWN IN &IG HAS
A DOUBLE CONVERSION CON`GURATION 4HE TO -(Z 5(& IS `RST MIXED DOWN TO
-(Z AMONG WHICH DESIRED #$-! CHAN
NEL IS SELECTED BY 3!7 `LTER IN THE `RST )&
BLOCK THEN TO -(Z 4WO DIVERSITY RE
CEIVERS 2CVR AND 2CVR ARE INCORPO
RATED IN ONE RECEIVER CARD 4HIS KIND OF RE
CEIVER IS A COMPONENT OF THE SPATIAL PATH
DIVERSITY FEATURE OF #$-! "OTH RECEIVERS
SHARE A COMMON 5(& LOCAL OSCILLATOR ,/
TO -(Z THAT IS GENERATED ON THE
UPCONVERTER CARD AND A COMMON -(Z
,/
4HE `RST ,.! ON THE RECEIVER CARD IS
A LOW NOISE AND HIGH THIRD ORDER INTERCEPT
POINT )0 AMPLI`ER &LOWER ATTENUATORS
GIVE THE INTERFACE BETWEEN THE 2&# CONTROL
AND THE VARIABLE ATTENUATORS WHICH PER
FORM CELL BLOSSOMING WILTING AND BREATH
ING FUNCTIONS 4HE 5(& IS DOWNCONVERTED
TO THE `RST )& OF -(Z 4HE MIXER HAS
A HIGH INTERCEPT POINT 4HE MIXER OUTPUT
IS DUPLEXED TO MAINTAIN BROADBAND TERMI
NATION FOR MIXER SPURS AND IS THEN SENT TO
THE `RST -(Z )& AMPLI`ER HIGH )0 AND
GAIN 3!7 ALONG WITH 3!7 LOCATED ON
THE `RST )& BLOCK PROVIDE THE SELECTIVITY
NEEDED TO MEET THE K(Z DESENSITIZATION
$ONG7OOK ,EE ET AL
SPECI`CATION 4HE REST OF THE -(Z )&
CHAIN CONSISTS OF A SEQUENCE OF GAIN BLOCKS
AND !'# !'# BLOCKS CONSIST OF 0). DIODE
AND ~PAD ATTENUATORS !'# DETECTOR IN
THE !'# CIRCUITRY CONSISTS OF 3CHOTTKY
DIODE TO SAMPLE THE -(Z ,OOP `L
TERING IS PERFORMED BY AN OPAMP INTEGRA
TOR ,OOP GAIN VARIATION IS MINIMIZED BY A
LINEARIZER 4HE ABSOLUTE SIGNAL STRENGTH IS
DERIVED FROM THE !'# 4HE -(Z CHAIN
CONSISTS OF A DUPLEXER FOLLOWED BY A MODER
ATE GAIN AMPLI`ER 4HE `NAL AMPLI`ER IS
FAIRLY ROBUST TO MAINTAIN SIGNAL INTEGRITY AT
AN OUTPUT LEVEL OF p D"M
4RANSMIT 0ATH 5NITS
! 4RANSMIT &RONTEND 5NIT
4HE 4RANSMIT &RONTEND 5NIT 4X&5
PROVIDES A SIGNAL PATH FOR FORWARD LINK BE
TWEEN THE (0!5 AND THE 4X ANTENNA !ND
THE MAIN FUNCTIONS OF THE 4X&5 ARE FORWARD
SIGNAL `LTERING AND SAMPLING /NE 4X&5
FOR SECTORS IS CON`GURED THREE BLOCK AND
EACH BLOCK STRUCTURE SHOWN IN &IG IS
COMPOSED OF 4X BANDPASS `LTER AND DIREC
TIONAL COUPLER 4HE 4X BANDPASS `LTER PRO
VIDES THE REJECTION OF OUTOFCELLULAR BAND
AND PASSES THE SERVICE BAND SIGNALS WHICH IS
DESIGNED WITH CAVITY TYPES FOR LOW INSERTION
LOSS AND GOOD SELECTIVITY )F MORE SUPPRES
SION ON BAND EDGE IS REQUIRED ADDITIONAL
NOTCH `LTER CAN BE USED 4HE DIRECTIONAL
COUPLER IS USED FOR SAMPLING TEST SIGNAL TO
"45 ON THE TRANSMIT PATH 4HE LEVEL OF
COUPLING OF THE TEST SIGNAL MUST MATCH THE
%42) *OURNAL VOLUME NUMBER /CTOBER !
&IG /NE BLOCK STRUCTURE OF THE 4X&5
2X&5 IN ORDER TO PROPERLY SIMULATE EQUAL
FORWARD AND REVERSE SIGNAL PATH LOSS
" 5PCONVERTER #ARD
4HE UPCONVERTER CARD PROVIDES THE FRE
QUENCY UPCONVERSION AS SHOWN IN &IG 4HE UPCONVERTER CARD RECEIVES THE -(Z
)& SIGNAL FROM THE 3)# AND UPCONVERTS THE
SIGNAL TO 5(& 4HE UPCONVERTER CARD `L
TERS THE SIGNAL TO REDUCE SPURIOUS ENERGY
LESS THAN u K(Z FROM THE CHANNEL CEN
TER )T ALSO PROVIDES GAIN ADJUSTMENT TO
THE TRANSMIT POWER TRACKING LOOP 404,
AND CELL BLOSSOMING WILTING AND BREATHING
FUNCTIONS INITIATED BY 2&#
4HE -(Z INPUT SIGNAL IS STARTED
WITH D" ATTENUATOR TO MEET THE IN
PUT 6372 SPECI`CATION AND TO REDUCE THE
SIGNAL TO THE REQUIRED LEVEL TO THE MIXER
4HE LOWPASS `LTER IS A NONTUNED ,# `LTER
THAT REDUCES THE NOISE BANDWIDTH AND HAR
MONICS OF THE INPUT SIGNAL 4HE D" POINT
OF THIS `LTER IS NORMALLY -(Z 4HE
LOWPASS `LTER IS FOLLOWED BY A RESISTIVE PAD
FOR IMPEDANCE MATCHING TO THE MIXER 4HE
TWO VARIABLE ATTENUATORS IN THE -(Z
)& SECTION ARE USED TO GIVE THE UPCONVERTER
$ONG7OOK ,EE ET AL
%42) *OURNAL VOLUME NUMBER /CTOBER 7%'*
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&IG "LOCK DIAGRAM OF THE FREQUENCY UPCONVERTER
VARIABLE GAIN CONTROL TO CORRECT FOR PROCESS
GAIN VARIATIONS OF THE ENTIRE FORWARD LINK
)N ADDITION THE PIN ATTENUATORS PROVIDE
ATTENUATION FOR CELL BLOSSOMING BREATHING
AND WILTING "OTH ATTENUATORS ARE CON
TROLLED BY A SINGLE ANALOG VOLTAGE THAT ORIG
INATES FROM 2&# 4HE TRANSMIT SIGNAL FRE
QUENCY -(Z TO -(Z IS OBTAINED
BY MIXING THE )& SIGNAL WITH 5(& ,/ !T
5(& THE DIELECTRIC BANDPASS `LTER YIELDS
D" OF ATTENUATION AT THE TRANSMIT ,/
FREQUENCIES -(Z TO -(Z 4HE
TRANSMIT ,/ FREQUENCIES ARE ALSO PROVIDED
FOR THE RECEIVER CARD ! -(Z PSEUDO
%#, BALANCED DI_ERENTIAL INPUT IS RECEIVED
FROM THE 2&# 4HIS SIGNAL IS USED AS A REF
ERENCE FOR A -(Z 0,, 4HE OUTPUT
OF THE 0,, IS SPLIT /NE HALF IS DIVIDED
BY FOUR TO YIELD THE -(Z )& ,/
4HE OTHER HALF IS DIVIDED BY `VE TO YIELD
-(Z 4HIS IS MIXED WITH THE 5(&
,/ REFERENCE FROM THE 2&# 4HIS SIGNAL
-(Z -(Z IS USED AS THE REF
ERENCE FOR THE 0,, THAT PRODUCES THE `NAL
-(Z TO -(Z 5(& ,/ 4HE 5(&
,/ REFERENCE GENERATED ON THE 2&# VARIES
FROM -(Z TO -(Z $$3 SYNTHE
SIZER ON THE 2&# CAN TUNE THE UPCONVERTER
TO ANY FREQUENCY WITH (Z RESOLUTION
BETWEEN -(Z AND -(Z 4HE
$ONG7OOK ,EE ET AL
SERIAL %%02/- HOLDS LINEARIZATION INFOR
MATION FOR THE 0). DIODE ATTENUATORS FOR
THE UPCONVERTER CARD
# (IGH 0OWER !MPLI`CATION 5NIT
4HE (IGH 0OWER !MPLI`CATION 5NIT
(0!5 PROVIDES A SIGNAL PATH FOR FORWARD
LINK BETWEEN THE $)35 AND THE 4X&% -AIN
FUNCTIONS OF THE (0!5 ARE AMPLI`CATION OF
SIGNAL FOR TRANSMITTING COMBINING TWO 2&
CHANNELS AND FORWARD POWER DETECTION FOR
TRANSMIT POWER TRACKING LOOP 404,
/NE (0!5 AS SHOWN IN &IG SUPPORTS
ONE SECTOR AND IS DESIGNED FOR &!S )T
IS COMPOSED OF TWO CLASS !" (0!S ONE
CHANNEL COMBINER AND TWO POWER DE
TECTOR %ACH (0! PROVIDES AMPLI`CATION OF
THE TRANSMIT SIGNAL AND THE SUPPRESSION OF
DISTORTION CAUSED BY INTERMODULATION PROD
UCT 4HE (0! IS CONTROLLED BY THE 2&# TO
CHANGE STATUS ENABLEDISABLE AND IS MONI
TORED IF IT IS IN THE RIGHT OPERATION %ACH
POWER DETECTOR RECEIVES THE COUPLING SIGNAL
FROM EACH (0! OUTPUT CONVERTS TO DC VOLT
AGE AND TRANSMIT TO THE 2&# FOR THE OPERA
TION OF 404, !LSO THE POWER DETECTOR HAS
DC VOLTAGE LEVEL DATA REPRESENTING THE (0!
OUTPUT SIGNAL LEVEL IN %%02/- /N INITIAL
IZATION OF "43 THE DATA IN %%02/- IS
READ BY THE 2&# AND USED AS REFERENCE DATA
FOR 404, OPERATION 4HE CHANNEL COMBINER
PROVIDES TWO CHANNEL COMBINING AND IS CON
`GURED BY THE ISOLATOR CHANNEL BANDPASS
`LTER AND THE COMBINER 4HE ISOLATOR PRO
TECTS (0! FROM RETURNING SIGNAL F CAUSED
BY MISMATCH AND SPILLING OVER OTHER CHANNEL
F %42) *OURNAL VOLUME NUMBER /CTOBER "
&'
"
"
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&IG ! STRUCTURE OF THE (0!5
6 #/.#,53)/.3
$ESIGN CONCEPT AND THE IMPLEMENTED
SYSTEM STRUCTURE OF THE #-3 ARE DESCRIBED
-OST OF PHYSICAL LAYER OPERATIONS BETWEEN
#$-! BASE STATION AND MOBILE STATION
AIR INTERFACE ARE PERFORMED IN THE #$-!
!3)#S AND THEIR CONTROL LOGIC CIRCUITS 4O
BE A COMMERCIAL SYSTEM THE BASE STATION
NEEDS TO BE HIGHLY INTEGRATED AND THE CRIT
ICAL MODULES OUGHT TO BE DUPLICATED !S A
COMMERCIAL PROTOTYPE SYSTEM EIGHT CHANNEL
ELEMENTS HAVE BEEN IMPLEMENTED IN A SIN
GLE CHANNEL CARD )T IS NOTICED THAT HIGHER
DENSITY CHANNEL CARD SUCH AS OR CHAN
NEL ELEMENTS PER CARD CAN BE REALIZED WITH
#3- MODEM !3)#S AND SOPHISTICATED CON
TROL SOFTWARE 4HE SPECI`CATIONS OF THE 2&
UNIT IS CHOSEN THROUGH THE SYSTEM LINK BUD
GET BASED ON MACROCELL COVERAGE 4O MAKE
THE SYSTEM RELIABLE THE SYSTEM IS DESIGNED
TO HAVE REDUNDANCY )T IS THE "#0 THAT
CON`GURES THE "43 DEVICES AND CONTROLS THE
%42) *OURNAL VOLUME NUMBER /CTOBER OVERALL OPERATIONS OF THE "43 4HE CALL CON
TROL ALGORITHM AND THE RESOURCE MANAGE
MENT ALGORITHM WITH CON`GURATION PARAM
ETERS PLAY A SIGNI`CANT ROLE IN THE OPTIMAL
CELL PLANNING 4HESE ALGORITHMS AND THE OP
ERATING PARAMETERS OF THE "#0 ARE BEING
VERI`ED AND IMPROVED THROUGH THE `ELD TEST
WITH THE HELP OF THE PERFORMANCE EVALUATION
$ONG7OOK ,EE ET AL
;= 'UILLERMO 'ONZALEZ -ICROWAVE 4RANSISTOR !M
PLI`ERS !NALYSIS AND $ESIGN 0RENTICE (ALL
;= 7ILLIAM #9 ,EE -OBILE #OMMUNICATIONS %N
GINEERING -C'RAW(ILL ;= 2OBERT # $IXON 3PREAD 3PECTRUM 3YSTEMS
*OHN 7ILEY 3ONS )NC $ONG7OOK ,EE
3EE %42) *OURNAL VOL NO P !PR TOOLS
2%&%2%.#%3
;= 44! 44! #OMMON !IR )NTERFACE FOR
$IGITAL #ELLULAR IN THE -(Z "AND +O
REA 4ELECOMMUNICATIONS 4ECHNOLOGY !SSOCIA
TION ;= 3 +IM 0 3ONG * +IM AND ( ,EE <)NVESTI
GATION OF #$-! AIR INTERFACE AND PROTOCOLS IN
THIS ISSUE PP ;= 1UALCOMM )NC #$-! "ASE 3TATION !3)#
5SER -ANUAL $,8 *AN ;= 1UALCOMM )NC #$-! #ELL 3ITE -ODEM !3)#
8 ;= $ONG7OOK ,EE *IN3U +IM 9OUNG'YUN
#HEONG AND -YOUNG *IN +IM <! METHOD
FOR CONTROLLING MULTIPURPOSED CHANNEL CARD IN
#$-! CELLULAR TELEPHONE SYSTEM APPLIED FOR
+OREA PATENT ;= - + 3IMON * + /MURA 2 ! 3CHOLTZ
AND " + ,EVITT 3PREAD 3PECTRUM #OMMUNICA
TIONS 6OL ))) #OMPUTER 3CIENCE 0RESS #HAP
;= ,EE AND -ESSERSCHMITT $IGITAL #OMMUNICATION
+!0 ;= 3TEPHEN * %RST 2ECEIVING 3YSTEM $ESIGN
!RTECH (OUSE ;= 7ILLIAM 'OSLING 2ADIO 2ECEIVER 0ETER 0ERRE
GRINUS ,TD +ISUK 9OO RECEIVED THE "3
AND -3 DEGREE FROM +O
REA 5NIVERSITY 3EOUL +OREA
IN RESPECTIVELY
ALL IN ELECTRONICS ENGINEERING
(E RECEIVED THE 0H$ DE
GREE IN ELECTRICAL ENGINEERING
FROM THE &LORIDA )NSTITUTE OF 4ECHNOLOGY -ELBOURNE
&LORIDA 53! IN 3INCE HE JOINED %42) IN
AS A 3ENIOR -EMBER OF 2ESEARCH 3TA_ HE HAS
BEEN WORKING FOR 2ADIO 4ECHNOLOGY 3ECTION IN -OBILE
4ELECOMMUNICATION $IVISION OF %42) (IS RESEARCH
INTERESTS ARE ROBUST CONTROL SYSTEM ESPECIALLY 2& SIG
NAL CONTROL AND 2& COMPONENTS
*IN3U +IM
3EE %42) *OURNAL VOL NO P !PR -YOUNG *IN +IM WAS BORN IN
/CTOBER IN 3EOUL +O
REA (E RECEIVED THE "3 AND
-3 DEGREES IN CONTROL AND
INSTRUMENTATION ENGINEERING
FROM 3EOUL .ATIONAL 5NIVER
SITY 3EOUL +OREA IN AND RESPECTIVELY AND THE 0H$ DEGREE IN ELEC
TRICAL ENGINEERING FROM THE 5NIVERSITY OF -INNESOTA
-INNEAPOLIS -INNESOTA IN $URING HE WORKED AT %42) 4AEJON +OREA WHERE HE WAS
INVOLVED IN RESEARCH AND DEVELOPMENT PROJECTS FOR
#$-! DIGITAL CELLULAR SYSTEM AND 0#3 3INCE $ONG7OOK ,EE ET AL
HE HAS BEEN AN ASSISTANT PROFESSOR AT THE $EPART
MENT OF )NFORMATION AND #OMMUNICATIONS %NGINEER
ING AT (ANKUK 5NIVERSITY OF &OREIGN 3TUDIES (5&3
9ONGIN +OREA (IS RESEARCH INTERESTS ARE CODE DIVI
SION MULTIPLE ACCESS WIRELESS COMMUNICATIONS AND
THEORY AND APPLICATION OF MULTISCALE TECHNIQUES AND
WAVELETS
*AE(ONG 0ARK (E RECEIVED
HIS "3 -3 AND 0H$ DE
GREES IN ELECTRICAL ENGINEERING
FROM 3EOUL .ATIONAL 5NIVER
SITY IN AND RESPECTIVELY (E DEVELOPED
ELECTRONIC WARFARE SYSTEM IN
!GENCY FOR $EFENCE $EVELOPMENT FROM TO 3INCE JOINING %42) IN HE HAD DEVELOPED SATEL
LITE SOMMUNICATION AND BROADCASTING SYSTEMS FOR +O
REASAT UNTIL #URRENTLY HE IS IN CHARGE OF 2ADIO
4ECHNOLOGY 3ECTION OF -OBILE 4ELECOMMUNICATION $I
VISION AND INVOLVED IN #$-! CELLULAR SYSTEM DEVEL
OPMENT AND 0#3 DEVELOPMENT (IS MAJOR INTERESTS
ARE MODULATION CHANNEL CODING AND RADIO COMMUNI
CATION SYSTEMS
%42) *OURNAL VOLUME NUMBER /CTOBER