EFFICIENT GENERATION OF SPREADING SEQUENCE CORRELATIONS USING LOOKUP TABLES

摘要

A signal is received containing a block of multiple symbols, each symbol containing information bits spread by a spreading sequence of chips. Each spreading sequence is determined by a channelization sequence and a first or second complex-valued scrambling sequence of chips. Each block is processed using a set of spreading sequences using correlations between pairs of spreading sequences in the set. Spreading sequence correlation values between each pair are manipulated and stored in lookup tables. A lookup table address is determined using a first set of reduced basic scrambling bits to retrieve correlation values. The first set of reduced basic scrambling bits is based on manipulation of one set of the basic scrambling bits that reduces a number of bits included in the determined address to less than a number of binary values in the one set of basic scrambling bits. The one set of basic scrambling bits is used to construct one of the first and second complex-valued scrambling sequences. The retrieved correlation values may be used in mitigating spreading sequence correlation interference between spreading sequences in the set.