| 摘要 |
In a lattice-reduction-aided receiver based wireless communications system, soft estimates of transmitted bit values are determined from a received signal by applying lattice reduction to the channel estimate and equalising the received signal in accordance with the reduced basis channel, and determining probabilities of transmitted bits having particular values. The method includes selecting an initial candidate vector in the reduced basis and determining further candidate vectors in the reduced basis dependently of the initial candidate vector, determining a corresponding transmitted symbol vector for each candidate vector and, on the basis of the received signal determining the probability of each transmitted bit value having been transmitted and log-likelihood ratios of transmitted bits. Determination of the log-likelihood ratio includes determining a first Euclidean distance corresponding to the initial symbol vector and a modified channel state matrix corresponding to the wireless communication system and then iteratively using the determined information to determine further Euclidean distances of further symbol vectors.
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