Collaborative uplink MIMO techniques for IEEE 802.16m

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Collaborative uplink MIMO techniques
for IEEE 802.16m
IEEE C802.16m-08/638r4
Document Number:
IEEE C802.16m-08/638r4
Date Submitted:
2008-07-14
Source:
Mohamed Abdallah
Mohammed Nafie
Cairo University, Cairo, Egypt
Re:
IEEE 802.16m-08/024: Call for Contributions on Project 802.16m System Description Document (SDD)
Uplink MIMO
Abstract :
This contribution proposes coding schemes to be included in the SDD
Purpose:
For discussion and approval by TGm
Note: This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It represents only the views of the participants
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material contained herein.
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Collaborative MIMO
IEEE C802.16m-08/638r4
• Mobile stations (MS) can transmit at the same time in
the same frequency
– Improve system throughput by employing collaborate
spatial multiplexing (CSM)
• Rate 2 by using 2 BS ant. x 1 MS ant. configuration. (adopted by
IEEE 802.16e)
• Rate 4 by using 4 BS ant. x 2 MS ant. configuration.
– Interference mitigation can be provided at the BS by
• Proper selection of the MSs based on channel conditions.
• Applying Precoding techniques at the MS.
Open Loop CSM
IEEE C802.16m-08/638r4
• 2 (M.S) x 4 (BS) OL collaborative spatial
multiplexing (CSM) can achieve system
throughput of rate 4
• Matrix A used at each MS
s 
A 
s 
1
2
• At the BS, the 4 streams can be separated
given that the two MSs are chosen properly.
Closed Loop CSM
IEEE C802.16m-08/638r4
• Precoding techniques can be applied at the MS for the
CSM.
– Improve the performance of the CSM.
• At each MS, a precoding 2x2 matrix V is chosen
from a codebook such that the mutual interference at
the BS is eliminated given a proper receiver.
• Due to the limited power constraint at the MS
– The precoding matrix V should limit the power transmitted
per antenna.
Proposed SDD Text
IEEE C802.16m-08/638r4
• 11.x.x. MU MIMO
– For open loop CSM mode, two MS with 2 transmit
antenna can cooperate together by sending their
data using matrix A to a 4 receive antennas at the
BS.
– For closed loop CSM mode, precoding is applied
at each MS where the 2x2 matrix V is properly
selected to separate the 2 streams of each MS
efficiently at the 4 ant. BS.
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