Patent ID: 7974357
Filing Date: 2011-07-05
Classification: H04L

Abstract:
1. A method for soft demodulation of data modulated according to a square quadrature amplitude modulation of order greater than or equal to 4, in a communication system implementing a multi-carrier code division multiple access or OFDM-CDMA technique, using non-binary spreading codes, comprising: determining a simplified expression for a logarithm of a likelihood ratio LLR(b where where m l,q corresponds to half of a distance between boundaries of a partition relating to b l,q and where: p σ N is a number of sub-carriers, l is an index representative of a sub-carrier (1≦l≦N), where the index is a positive integer, c ĥ y and determining a simplified expression for a logarithm of a likelihood ratio LLR(b where where m Q,q corresponds to half of a distance between boundaries of a partition relating to b Q,q and where: y