1. CoFIP Pilot Sequences Document Number: IEEE C 80216m-09_2239r2 Date Submitted: 2009-17-05 Source: Padmanabhan M S, Kiran Kuchi, J. Klutto Milleth, SivakishoreVoice: CEWiT, IndiaE-mail: kkuchi@cewit.org.in, klutto@cewit.org.in Venue: Comments on P802.16m/D2 (15.3.11.3.3) Base Contribution: None Purpose: To discuss and adopt the proposed text in D3 To discuss in TGm for appropriate action. Notice: 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 discussion. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material contained herein. Release: 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 any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.16. Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and.http://standards.ieee.org/guides/bylaws/sect6-7.html#6http://standards.ieee.org/guides/opman/sect6.html#6.3 Further information is located at and.http://standards.ieee.org/board/pat/pat-material.htmlhttp://standards.ieee.org/board/pat

2. CoFIP pilot sequences specification

3. Pilot sequences for CDR with CoFIP The pilot sequences assigned to different cells should have low cross correlation within the space of an RB. Some of the possibilities are:  Use of short pilot sequences, which have low cross-correlation within a localized resource unit.  Use of long PN sequences Results in increased cross correlation

4. Short PN sequence Seven PN sequences are generated using an LFSR with the characteristic polynomial X 3 +X +1 The first 6 samples of a sequence is used for deriving the 6 pilots with in a PRU Definitions:  A cluster is a collection of 3 sectors and is assigned unique cluster id = CID  PRU index ‘s’ in frequency and sub-frame number ‘t’ in time. Pilot codebook C = { c(0),c(1),c(2), c(3), c(4),c(5), c(6) } is defined in table 1.

5. Pilot codebook Table 1

6. Pilot sequence cycling Pilot sequence cycling in time and/or frequency is implemented to exploit the advantage of interference averaging on the pilots. The pilot code used in a cell with CID = k is C( (s+t+k)%7), where C(i) is the i th code of the set of codes C. i=0,1,…6 CID = 0 CID=1 CID=2 s t -->

7. CDR Performance comparison between short and long PRBS

8. Proposed Text ……………………..Start of Text………………………………………………………. Section 15.3.11.3.3, Page 541, line 56 In Type 1 OL MIMO region, the pilot sequence used to modulate the six COFIP pilot tones shall be obtained from the pilot codebook C defined in Table xxx. The code used in a PRU in a cell with cluster_ID = k is C( (s+t+k) mod 7), where ‘s’ is the physical PRU index and ‘t’ is the physical subframe index, and C(i) is the i th code defined in Table xxx with i=0,1,…6. Each entry of the sequence corresponding to C(i) shall be used to modulate the 6-pilot tones in the order shown in Figure xxx, yyy and zzz where P(j) denotes the jth entry of C(i)

9. Table xxx Pilot Code Book for CoFIP Pilot CodeSequence C(0)[-1 -1 1 1 1 -1] C(1)[-1 1 -1 -1 1 1] C(2)[-1 1 1 1 -1 1] C(3)[1 -1 -1 1 1 1] C(4)[1 -1 1 -1 -1 1] C(5)[1 1 -1 1 -1 -1] C(6)[1 1 1 -1 1 -1]

10. XP(0) XXP(1)X XP(2)X P(3)XX XXP(4)XX P(0)XXP(1)XX XXP(2) XP(3)X XP(4)XXP(5)X XXP(0)XXP(1) P(2)XX XXP(3) P(4)XXP(5)XX Figure xxx – Pilot Modulation for CoFIP Tones for AAI sub frames with 6 OFDM symbols Pilot pattern set 0 Pilot pattern set 1Pilot pattern set 2 6 symbols 18 contiguous subcarriers

11. XP(0) XXP(1)XX XP(2)XX P(3)XX XXP(4)XXX P(0)XXP(1)XXP(0) XXP(2)X XP(3)XX XP(4)XXP(5)XX XXP(0)XXP(1)X P(2)XX XXP(3)X P(4)XXP(5)XXP(4) Figure yyy – Pilot Modulation for CoFIP Tones for AAI sub frames with 7 OFDM symbols Pilot pattern set 0 Pilot pattern set 1Pilot pattern set 2 7 symbols 18 contiguous subcarriers

12. XP(0) XXP(1) XP(2)XX P(3)XP(4)X XXP(5)XX P(0)XXP(1)X XXXP(2) XP(3)XX XP(4)XXP(5) XXP(0)XX P(1)XP(2)X XXXP(3) P(4)XXP(5)X Figure zzz - – Pilot Modulation for CoFIP Tones for AAI sub frames with 5 OFDM symbols ……………………..End of Text………………………………………………………. Pilot pattern set 0 Pilot pattern set 1Pilot pattern set 2 5 symbols 18 contiguous subcarriers