1. SC PHY EDMG-CEF Design for Channel Bonding x3
September 2016
doc.: IEEE /XXXXr0
September 2016
SC PHY EDMG-CEF Design for Channel Bonding x3
Date:
Authors:
Intel Corporation
Intel Corporation

2. September 2016
Introduction
This presentation proposes a design of the Channel Estimation Field (CEF) for SC PHY in case of channel bonding of x3.
The proposed design covers SISO and MIMO cases.
Intel Corporation

3. September 2016
Problem Statement
The presentation [1] defines the real value Golay sequences for EDMG-STF/CEF field in case of SISO and MIMO.
The definitions are introduced for the single channel and channel bonding CB = 2 and 4. The supported Golay sequence lengths are equal to 128, 256, and 512.
The transmission using channel bonding x3 requires introduction of Golay sequence of length 384. It is well known that bipolar Golay sequences of this length do not exist.
Intel Corporation

4. Proposed Solution The proposed solution: September 2016
The proposed solution uses a quadri-phase complex Golay complementary pairs instead of real value bipolar Golay sequences;
The Golay complex sequences use in their definition not just {±1} elements, but rather supplement them with {±j} elements forming a complex set {±1, ±j};
The complex Golay complementary pair of length 3 can be defined as follows:
Ga3 = [+1, +1, -1];
Gb3 = [+1, +j, +1];
Here the Gb3 sequence uses in their definition +j extra element;
Using these basic sequences one can get the sequences of length 384 required for the CEF x3 definition;
Intel Corporation

5. Proposed Solution (Cont’d)
September 2016
Proposed Solution (Cont’d)
Proposed solution (cont’d):
In order to get a required length of 384 for Ga384 and Gb384 sequences to be used in the CEF definition, one needs to apply the following recursive operation:
A0(n) = Ga3(2-n);
B0(n) = Gb3(2-n);
Ak(n) = Wk*Ak-1(n) + Bk-1(n-Dk);
Bk(n) = Wk*Ak-1(n) – Bk-1(n-Dk);
NOTE: the difference from the standard definition is that A0(n) and B0(n) sequences at the zero iteration are not Dirac delta functions, but rather Ga3(2-n) and Gb3(2-n) introduced at the previous slide, order of samples is inverted;
Starting from the length N = 3 and making 7 iterations, one will get 128 * 3 = 384 the required sequence length;
The vector Dk is defined as delay vector for N = 128, but all its elements are multiplied by 3, the weight vector Wk is kept unchanged as for N = 128:
Dk = [ ] * 3;
Wk = [ ];
Intel Corporation

6. Proposed Solution (Cont’d)
September 2016
Proposed Solution (Cont’d)
EDMG-CEF x3 definition:
Definition of Ga384 and Gb384 sequences:
Ga384(n) = conj(A7(383-n)), Gb384(n) = conj(B7(383-n));
Then the Gu1536 and Gv1536 sequences of the CEF can be defined as follows:
Gu1536 = [-Gb384, -Ga384, +Gb384, -Ga384];
Gv1536 = [-Gb384, +Ga384, -Gb384, -Ga384];
This makes Gu1536 and Gv1536 sequences complementary and solves the issue with channel estimation in frequency domain;
NOTE: once per 6 symbols the phase of adjacent samples will experience π-radian flip, even after application of exp(jπ/2*n) rotation, however this does not affect much the PAPR properties of the signal at the output of pulse shaping filter;
Intel Corporation

7. Proposed Ga384/Gb384 Sequences
September 2016
Proposed Ga384/Gb384 Sequences
Sequences:
NOTE: ±j element appears once per 6 symbols, therefore does not affect much PAPR;
Intel Corporation

8. Golay Generator for x3 Golay generator scheme: September 2016
Based on the Ga128/Gb128 sequence generator;
Multiplies all delays (except of D = 1) by a factor of 3;
Requires modification of the first “butterfly” for delay D = 1 and replace it by D = 5;
Total number of delays:
Ga128/Gb128: 127 delays = ;
Ga256/Gb256: 255 delays = ;
Ga384/Gb384: 383 delays = ;
Ga512/Gb512: 511 delays = ;
In all cases the number of delays is equal to N-1, where N is a length of the sequence;
Next slide shows Golay generator scheme for the sequences Ga384/Gb384;
Intel Corporation

9. Golay Generator for x3 (Cont’d)
September 2016
Golay Generator for x3 (Cont’d)
Golay generator for Ga384/Gb384:
Ga384(n)/Gb384(n) are defined as inverted in time and conjugated sequences:
Ga384(n) = conj(A7(383-n)), Gb384(n) = conj(B7(383-n));
Z in the picture defines a delay unit;
Golay correlator has the same structure;
Intel Corporation

10. PAPR Signal Properties
September 2016
PAPR Signal Properties
Compared CEF signal definitions:
Using Ga256/Gb256:
Gu1536 = [-Gb256, -Ga256, +Gb256, -Ga256, -Gb256, +Ga256];
Gv1536 = [-Gb256, +Ga256, -Gb256, -Ga256, +Gb256, -Ga256];
Using Ga384/Gb384:
Gu1536 = [-Gb384, -Ga384, +Gb384, -Ga384];
Gv1536 = [-Gb384, +Ga384, -Gb384, -Ga384];
PAPR estimation:
At the output of pulse shaping filter defined in the 11ad std. at the 2.64 GHz sample rate, [2];
Results:
Using Ga256/Gb256: PAPR = 3.11 dB;
Using Ga384/Gb384: PAPR = 2.93 dB;
Conclusion:
Similar properties;
Intel Corporation

11. September 2016
Proposed GSS for MIMO
Proposed delay vector and weight vector for MIMO GSS:
Delay vector is fixed and not dependent on the stream number:
Dk = [3, 24, 6, 12, 48, 96, 192];
Weight vector depends on the stream number:
Streams 1 and 2: Wk = [-1,-1,-1,-1,+1,-1,-1];
Streams 3 and 4: Wk = [-1,-1,-1,+1,-1,-1,+1];
Streams 5 and 6: Wk = [-1,-1,-1,+1,-1,+1,+1];
Streams 7 and 8: Wk = [-1,-1,-1,+1,+1,+1,-1];
Input definition:
Streams 1, 3, 5, 7: (A0(n), B0(n)) = (+Ga3(2-n), +Gb3(2-n));
Streams 2, 4, 6, 8: (A0(n), B0(n)) = (+conj(Gb3(2-n)), -conj(Ga3(2-n))) – ZCC sequences;
To obtain the ZCC sequences for the streams 2, 4, 6, and 8 simple modification of the first butterfly is required: switch between A and B, complex conjugation and sign inversion;
Output definition:
Streams 1 - 8: (Ga384(n), Gb384(n)) = (+conj(A7(383-n)), +conj(B7(383-n)));
Intel Corporation

12. Golay Set Properties Analysis N = 384
September 2016
Golay Set Properties Analysis N = 384
Figure below shows MF output for 8 sequences in the set, for Ga and Gb separately. It is shown that all sequences in the set have very similar autocorrelation properties (except of side lobes).
Shaping filter is used as defined in the 11ad std., [2].
Graphs are shown after application of Matlab FFT shift function.
Ga sequences
Gb sequences
Intel Corporation

13. September 2016
Conclusions
This presentation proposes EDMG-CEF field design for SC PHY in case of three channels bonding for SISO and MIMO transmission.
Intel Corporation

14. Straw Poll Do you agree to insert the following into the SFD:
September 2016
Straw Poll
Do you agree to insert the following into the SFD:
“11ay specification shall define the Golay sequences of length 384 for EDMG-CEF to support CB=3 defined in ay on slides 5, 6, and 11 using the EDMG-CEF structure defined in the SFD.”
Intel Corporation

15. September 2016
References
ay-EDMG-STF-and-CEF-design-for-SC-PHY-in-11ay
Draft P802.11REVmc_D5.4
Intel Corporation