A maximum contention-free quadratic permutation interleaver is defined as Short length interleaver: Long length interleaver: where is the length of interleaver. Elements of codewords (ci for are i=0,1,…,NI-1. NI i=0,1,…,n-1) interleaved in blocks of bits as c∏(j) for NI j=0,1,…,NI-1. 6.9 Scrambling A scrambler is used to the data spectrum and to randomize data across users in order to reduce interference. A Gold code generator of length 63 is proposed as scrambler. Such PN sequence with period 263 appears truly random even for long packets. Moreover, different initialization seeds enable a different Gold code per user with low correlation respect to other user using a different seed. The Gold code generator outputs si for which is used to scramble the interleaved i=0,1,…,263-1, codeword bits for prior to the modulation mapper as ci i=0,1,…,n-1 The shift registers initialization at the start of a packet is given by User ID (1st register) and group ID (2nd register). Fast forward both shift registers 100 times to reduce PAPR. 6.10 Discovery
A maximum contention-free quadratic permutation interleaver is defined as Short length interleaver: Long length interleaver: where i=0,1,…,NI-1. NI is the length of interleaver. Elements of codewords (ci for i=0,1,…,n-1) are interleaved in blocks of NI bits as c∏(j) for j=0,1,…,NI-1. 6.9 Scrambling A scrambler is used to the data spectrum and to randomize data across users in order to reduce interference. A Gold code generator of length 63 is proposed as scrambler. Such PN sequence with period 263 appears truly random even for long packets. Moreover, different initialization seeds enable a different Gold code per user with low correlation respect to other user using a different seed. The Gold code generator outputs si for i=0,1,…,263-1, which is used to scramble the interleaved codeword bits ci for i=0,1,…,n-1 prior to the modulation mapper as The shift registers initialization at the start of a packet is given by User ID (1st register) and group ID (2nd register). Fast forward both shift registers 100 times to reduce PAPR. 6.10 Discovery
15-13-0707-01-0008-nict-phy-proposal-document-short-version.docx