IEEE C802.16maint-08/218r2
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
3-Bit 2-Transmit and 4-bit 4-Transmit Antenna Codebooks for Closed-Loop MIMO
Date
Submitted
2008-06-20
Source(s)
Louay Jalloul, Beceem
[email protected]
Ron Porat, Wee Peng Goh, Nextwave
Shkalim, Runcom
Herbert Ruck, Cisco Systems
Re:
Letter Ballot 26d
Abstract
We propose new 3-Bit 2-transmit and 4-bit 4-transmit antenna codebooks for CL-MIMO that
outperform the 16e codebooks due the per antenna power constraint. The newly proposed
codebooks also are more implementation friendly than the 16e designs, thus, simplifying the MS
search procedure.
Purpose
Adopt the proposed specification changes in IEEE P802.16Rev2
Notice
Release
Patent
Policy
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 listed in the “Source(s)” field above. It is offered as a basis for
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contained herein.
The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution,
and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name
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<http://standards.ieee.org/guides/bylaws/sect6-7.html#6> and
<http://standards.ieee.org/guides/opman/sect6.html#6.3>.
Further information is located at <http://standards.ieee.org/board/pat/pat-material.html> and
<http://standards.ieee.org/board/pat>.
3-Bit 2-Transmit and 4-bit 4-Transmit Antenna Codebooks for Closed-Loop
MIMO
Louay Jalloul, Beceem
Ron Porat, Nextwave
1. Introduction
The current codebooks for closed-loop MIMO in the 16e standard suffer from severe performance degradation
due to the fact that these codebook designs ignored the issue of the per-antenna power constraint. New
codebooks for 2-transmit and 4-transmit antennas are described in this contribution that are constant modulus
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IEEE C802.16maint-08/218r2
and as such are power balanced.
In a noise limited scenario (or a lightly loaded system), the 16e 2-transmit antenna codebook looses about 2 or
3dB (depending on the method of applying the power constraint at the BS) relative to the newly proposed
constant modulus codebook. A larger loss is seen for the 4-antenna codebook, around 3 to 7dB, relative to the
newly proposed constant modulus 4-bit codebook. Note that in a heavily loaded system, where many users are
scheduled, then the per antenna power constraint doesn’t lead to much of a degradation and the 16e codebooks
perform as good as the newly proposed codebooks.
The newly proposed codebooks for both the 2-transmit and 4-transmit antennas are constructed using a
quaternary alphabet which greatly simplifies the codeword search at the SS.
Another advantage of the newly proposed 4-transmit antenna codebook is that it based on a 4-bit codebook (16
codewords) as opposed to the 6-bit codebook in 16e.
2. Newly Proposed 3-Bit 2-Transmit Antenna Codebook
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IEEE C802.16maint-08/218r2
Codebook
index
Number of layers

1
2
0
1 1
 
2 1
1 1 1 


2 1 1
1
1 1
 
2  1
2
1  1 
 
2  j 
1  1 1
2  1 1
1  1 1
2   j j 
3
1 1 
 
2  j
4
1  1 1 j 


2 
2 

5
6
7
1
2
1 1

2j
 1 
1  j 
 2 
1   11

2
2

1   11

2
2


j


j

1 

 j
1 1 1 j

2
 2
1
1
2

j

1 1 1 j

2
 2
1
1
2

j

1   11 j

2
2

1   11 j

2
2

1 
1 j
2 
1 
1 j
2 
3. Performance of 16e codebooks
See companion slides S80216mait-08_218.ppt.
4. Conclusion
We recommend adopting the newly proposed 3-bit 2-transmit and 4-bit 4-antenna codebooks.
5. Text Changes
[Add the following text to Rev2/D5at the end of section 8.4.5.4.10.15, page 866, line 19]
The 2-transmit and 4-transmit antenna codebooks using the quaternary alphabet {1, j, -1, -j} are shown in Table
xxx and Table yyy, respectively.
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IEEE C802.16maint-08/218r2
Table xxx – 3-Bit 2-Transmit antenna Codebook based on Quaternary alphabet.
Codebook
index
Number of layers

1
2
0
1 1

2 1
1 1 1 


2 1 1
1
1 1
 
2  1
2
1 1
 
2  j 
1  1 1
2  1 1
1  1 1
2   j j 
3
1 1 
 
2  j
1 1 1 


2  j  j
4
1  1 1 j 


2  2 


1 1 1 j

2
 2
1
1
2

j

5
1 1 1 j 


2 2 


1 1 1 j

2
 2
1
1
2

j

6
7
1   11

2 2

1   11

2 2


j


j

1   11 j 1 1 j 


2
2 
 2
1   11 j 1 1 j 


2
2 
 2
Table yyy – 4-Bit 4-Transmit antenna Codebook based on Quaternary alphabet.
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IEEE C802.16maint-08/218r2
Codebook Index
0
1
2
3
4
5
6
7
Rank 1
 j 
 
1 1 
2  j 
 
  1
 j 
 
1   1
2  j 
 
1 
 j 
 
1 1 
2 j 
 
1 
 j 
 
1   1
2 j 
 
 j 
  1
 
1  j 
2  j 
 
1 
  1
 
1  j 
2 j 
 
  1
 j 
 
1   1
2   1
 
 j 
 j
 
11 
2  1
 
 j
5
Rank 2
[V0 V1]
Rank 3
[V1 V2 V3]
[V1 V3]
[V0 V2 V3]
[V2 V3]
[V0 V1 V3]
[V0 V2]
[V0 V1 V2]
[V4 V5]
[V5 V6 V7]
[V5 V7]
[V4 V6 V7]
[V6 V7]
[V4 V5 V7]
[V4 V6]
[V4 V5 V6]
IEEE C802.16maint-08/218r2
8
9
10
11
12
13
14
15
  1
 
1   1
2 j 
 
 j 
 j
 
1 j 
2  1
 
1
 j 
 
1  j 
2   1
 
  1
1 
 
1   1
2  j 
 
 j 
 j
 
1  j
2  j
 
 j
1
 
1  1
21 
 
 1
 j 
 
1 j 
2  j 
 
 j 
 1
 
11 
21 
 
 1
6
[V8 V9]
[V9 V10 V11]
[V9 V11]
[V8 V10 V11]
[V10 V11]
[V8 V9 V11]
[V8 V10]
[V8 V9 V10]
[V12 V13]
[V13 V14
V15]
[V13 V15]
[V12 V14
V15]
[V14 V15]
[V12 V13
V15]
[V12 V14]
[V12 V13
V14]