A communication signal receiver comprising: an input for receiving an orthogonal frequency division multiplexing (OFDM) communication signal, the communication signal comprising signal components comprising respective sub-carrier signals; and a processor adapted to receive the communication signal from the input, and, for at least a first of the signal components, to perform operations including: applying space-time transmit diversity (STTD) decoding to the communication signal to obtain decoder outputs; generating a first initial soft-demapping value based on a first of the decoder outputs; computing a first scalar value based at least on the first decoder output and a corresponding hard-decision value, wherein said computing the first scalar value allows a first noise power (σ 1 (k)) 2 associated with the first signal component and a second noise power (σ 2 (k)) 2 associated with the first signal component to be different, wherein the first noise power (σ 1 (k)) 2 is an estimated power of a first noise signal contained in the first signal component during a first symbol time within a current STTD block, wherein the second noise power (σ 2 (k)) 2 is an estimated power of a second noise signal contained in the first signal component during a second symbol time within the current STTD block; multiplying the first initial soft-demapping value by the first scalar value to obtain a first modified soft-demapping value; wherein the processor comprises an interference estimator for estimating the first scalar value, and a decoder adapted for connection to the interference estimator and to the input, wherein the decoder is configured to perform said STTD decoding. an input for receiving an orthogonal frequency division multiplexing (OFDM) communication signal, the communication signal comprising signal components comprising respective sub-carrier signals; and a processor adapted to receive the communication signal from the input, and, for at least a first of the signal components, to perform operations including: applying space-time transmit diversity (STTD) decoding to the communication signal to obtain decoder outputs; generating a first initial soft-demapping value based on a first of the decoder outputs; computing a first scalar value based at least on the first decoder output and a corresponding hard-decision value, wherein said computing the first scalar value allows a first noise power (σ 1 (k)) 2 associated with the first signal component and a second noise power (σ 2 (k)) 2 associated with the first signal component to be different, wherein the first noise power (σ 1 (k)) 2 is an estimated power of a first noise signal contained in the first signal component during a first symbol time within a current STTD block, wherein the second noise power (σ 2 (k)) 2 is an estimated power of a second noise signal contained in the first signal component during a second symbol time within the current STTD block; multiplying the first initial soft-demapping value by the first scalar value to obtain a first modified soft-demapping value; wherein the processor comprises an interference estimator for estimating the first scalar value, and a decoder adapted for connection to the interference estimator and to the input, wherein the decoder is configured to perform said STTD decoding. applying space-time transmit diversity (STTD) decoding to the communication signal to obtain decoder outputs; generating a first initial soft-demapping value based on a first of the decoder outputs; computing a first scalar value based at least on the first decoder output and a corresponding hard-decision value, wherein said computing the first scalar value allows a first noise power (σ 1 (k)) 2 associated with the first signal component and a second noise power (σ 2 (k)) 2 associated with the first signal component to be different, wherein the first noise power (σ 1 (k)) 2 is an estimated power of a first noise signal contained in the first signal component during a first symbol time within a current STTD block, wherein the second noise power (σ 2 (k)) 2 is an estimated power of a second noise signal contained in the first signal component during a second symbol time within the current STTD block; multiplying the first initial soft-demapping value by the first scalar value to obtain a first modified soft-demapping value; wherein the processor comprises an interference estimator for estimating the first scalar value, and a decoder adapted for connection to the interference estimator and to the input, wherein the decoder is configured to perform said STTD decoding.