Method and apparatus for calculating likelihood metric of a received signal in a digital communication system

摘要

A likelihood metric calculation method including: estimating a channel of a received signal and generating a channel estimate; compensating a channel of the received signal according to the channel estimate; calculating a region variable according to the channel estimate; and comparing the region variable and a magnitude of the compensated received signal and calculating a likelihood metric of the received signal according to a result of the comparison. An apparatus for calculating a likelihood metric including: a channel estimation unit estimating a channel of the received signal and generating a channel estimate; a channel compensation unit compensating a channel of the received signal according to the channel estimate; a region variable calculation unit calculating a region variable according to the channel estimate, the region variable being a value obtained by scaling a symbol coordinate value in a signal constellation corresponding to the received signal utilizing the channel estimate; a comparison unit comparing a magnitude of the compensated received signal and the region variable; and a bit metric calculation unit calculating a likelihood metric with respect to each bit of the compensated received signal according to a result of the comparison. According to the present invention, it is possible to reduce a complexity in the compensating of the channel and the calculating of the likelihood metric. Also, since effects caused by the channel variation are reflected as a weighting factor in the calculating of the likelihood metric, it is possible to improve a message detection performance of the entire system.