1. Uplink MIMO proposal for IEEE 802.16m
Document Number: C80216m-08/538r1
Date Submitted:
Source:
Alexei Davydov[2]
Yang-seok Choi[1] Voice: [1], [2]
Alexander Maltsev[2]
Intel Corporation [1]Portland, OR, US
[2] Russia, Nizhny Novgorod, Ul. Turgeneva, 30
Venue:
Call for contributions on project m SDD: Uplink MIMO
Session #56: Denver, USA
Base Contribution:
IEEE C80216m-08/538r1
Purpose:
For discussion and adoption by IEEE m group
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2. Generic Block Diagram for UL MIMO
Precoded Antenna Symbols
Data bits
QAM Symbols
Number of Spatial Channels NSCH
Number of Spatial Streams NSS
Number of Transmit Antennas NTX
Coded bits
Space Frequency (Time) Encoded Symbols

3. Space Frequency Block Codes
Rate – 2
Rate – 1
In accordance to IEEE m system requirement document the system shall support the connection up to the highest supported speed of 350 kmph
Space Time Block Code (STBC) is not appropriate for such high speeds due to loss of orthogonality in fast channel fading
Space-frequency Block Code (SFBC) should be considered as a baseline scheme for IEEE m due to it’s robustness to the mobility
Space Frequency Block Codes offers other advantages:
Less buffering requirements – the decoding is performed for single OFMDA symbol
Flexible to any frame structure design – easy to satisfy the requirement on even number interval transmissions

4. SFBC Link Layer Performance
Baseline SIMO in Ped.-B (3kmph)
SFBC-A in Ped.-B (3kmph)
SFBC-A in Veh.-A (60 kmph)
SFBC-A in Veh.-A (120 kmph)

5. SFBC Link Layer Performance (Cont’d)
Matrix A rank-1 transmission
Matrix B rank-2 transmission

6. Collaborative MIMO
MS 1
MS 1
Base Station
MS 1
Base Station
Base Station
MS 2
MS 2
MS 2
The UL network capacity is limited by the peak data rate of MS due to
channel bandwidth, low modulation order and transmit power limitations
small number of transmit antennas at the MS due to
small form factor of hand held MS devices
higher implementation cost of multiple power amplifiers
Collaborative MIMO is an effective solution to increase the network capacity in the UL for such scenario
collaborative MS may reuse the same time-frequency resource and transmit data simultaneously
collaborative MS uses orthogonal pilot allocation to enable MIMO processing at the BS
The efficiency of interference mitigation at the BS is provided by
proper scheduling of collaborative MS
Codebook precoding may be used to improve the efficiency of collaborative MIMO
IEEE m should support up to four simultaneous streams transmission

7. Collaborative MIMO Link Layer Performance
Spatial Multiplexing
Further gain of collaborative MIMO over SU-MIMO spatial multiplexing may be achieved by proper MS scheduling and pairing

8. UL MIMO Codebook Based PrecodingMS
Base Station
The usage of the precoding at the MS is essential to achieve IEEE m requirements
Legacy IEEE802.16e codebook is not constant modulus scheme and causes antenna power imbalance problem for power limited MS
Low PAPR codebooks constructions is required for IEEE m UL MIMO
Constant amplitude with antenna subset selection codebook (see next slide)
Example 1-TX (4 antenna MS) rate-1 antenna selection codebook construction

9. Constant Amplitude with Antenna Subset Selection Codebook Construction
Selection of the TX antenna subset
Constant amplitude codebook with antenna subset selection
Constant amplitude baseline codebook
Antenna selection matrix
Precoding on selected antenna subset
Advantages of the proposed codebooks
Low PAPR
Structured construction
Easy extensible to any number of MS antennas
Optimized to power-limited MS
Limits the actual number of transmitting antenna

10. Precoding Link Layer Performance

11. Summary of Proposed Uplink MIMO Modes
SU-MIMO
Rate 1
Transmit Diversity
Space Frequency Block Code (SFBC)
Open loop and codebook precoding
Rate 2
Spatial Multiplexing
Single Codeword (SCW)
MU-MIMO
Up to four parallel spatial streams
Open loop and precoded collaborative MIMO
Two stage codebook precoding
antenna subset selection
constant amplitude precoding on selected antenna subset

12. Proposed Text for SDD (Cont’d)

13. Proposed Text for SDD (Cont’d)