Patent ID: 7613158
Filing Date: 2009-11-03
Classification: H04B

Abstract:
1. A method of quadrature spreading by an M bit processor in a code division multiple access communication (CDMA) system, the method comprising: adding a bit of each of N data channels together to obtain a combined channel value represented by K bits where K is the smallest number of bits which is required to represent N in binary and which is a factor of M; packing S combined channel values into an M bit combined channel data element, where S×K=M; extending M/N bits of short code to M bits by repeating each bit of short code N times to produce an extended short code; and XORing the combined channel data element with the extended short code to obtain an N channel M bit spread channel value, wherein the XORing comprises a spreading operation: and wherein said spreading operation is performed by: providing constant data having M bits in which a binary sequence representing the number of channels N is repeated S times; performing a first manipulation of said combined channel data by logically AND-ing said combined channel data with said short code data to thereby obtain first manipulated combined channel data; performing a second manipulation of said combined channel data by (a) subtracting said combined channel data from said constant data to obtain first intermediate data and (b) logically AND-ing said intermediate data with the inverse of said short code data to thereby obtain second manipulated combined channel data; logically OR-ing said first and second manipulated combined channel data; and subtracting said logically OR-ed first and second manipulated combined channel data from said constant data to obtain said spread channel data.