Patent ID: 7453959

Claim:
An apparatus for erasure detection and soft-decision decoding in a cellular system receiver for decoding a code block received from a cellular system transmitter, comprising: a channel gain and noise variance estimator for estimating a complex channel gain and a noise variance of the received code block; an erasure detector for detecting an erasure symbol (a received symbol with high power interference) by comparing a threshold value based on the estimated complex channel gain or the noise variance with power of the received symbol; a soft-decision decoding metric calculator for setting log-likelihood ratios of constituent bits of the erasure symbols to be 0 and computing the log-likelihood ratios of the constituent bits of other received symbols; and a soft-decision channel decoder for decoding the received code block with the calculated log-likelihood ratios, wherein the erasure detector detects the received symbol as the erasure symbol when the power of the received symbol is greater than the threshold value, wherein the threshold value includes a value which is determined based on a sum of the power of the fading channel gain of the received symbol and a constant multiple of an average noise variance.