Patent ID: 9042493
Filing Date: 2015-05-26
Classification: H04B,H04L

Abstract:
1. A communication apparatus with a multiple-input and multiple-output (MIMO) channel, the communication apparatus comprising: a minimum mean square error (MMSE) detector configured to estimate quadrature amplitude modulation (QAM) symbols based on signals received through the MIMO channel; a QAM demodulator configured to demodulate the estimated QAM symbols, and estimate a first posterior probability of each of encoded bits of the estimated QAM symbols; a first module configured to remove a first prior probability of each of the encoded bits from the first posterior probability to generate soft estimates of the encoded bits; a channel decoder configured to decode the encoded bits based on the soft estimates, and generate an improved posterior probability of each of the encoded bits; a second module configured to generate a second prior probability of each of the encoded bits based on the improved posterior probability, the second prior probability being a first prior probability of each of encoded bits of QAM symbols in a next iteration cycle; a hard-decision estimator configured to generate a sequence of hard estimates of information bits based on the improved posterior probability; a remodulator configured to generate a first mathematical expectation and a first variance of the QAM symbols based on the improved posterior probability; and a third module configured to compare the first variance with a third variance generated after estimation of QAM symbols in a previous iteration cycle, and generate input parameters of the MMSE detector based on a result of the comparing.