Patent ID: 9020076
Filing Date: 2015-04-28
Classification: H04B,H04L

Abstract:
1. A communication apparatus which receives through a transmission path a combined signal in which a plurality of modulated signals including transmission symbol information are combined, the communication apparatus comprising: a lattice basis reduction unit which converts a channel matrix indicating transmission characteristics of the transmission path using a basis conversion matrix; a transmission symbol estimation unit which estimates a transmission symbol from the received combined signal using the converted channel matrix; a bit likelihood calculator which calculates, at a reduced basis, a likelihood of each bit of the estimated transmission symbol being a predetermined value using an inverse matrix of the basis conversion matrix, the bit likelihood calculator comprising a candidate symbol selector selects a signal point including a logical negation bit of each bit of the estimated transmission signal as a candidate symbol corresponding to each bit of the estimated transmission signal; and a basis inverse converter which basis converts the selected candidate symbol using the inverse matrix of the basis conversion matrix.