A receiver for detecting a signal, comprising: an input module for receiving a signal transmitted over a communications channel, the received signal comprising a plurality, M, of observed signal components from a predetermined alphabet, and the input module arranged to receive information describing the transmission of the signal over the communications channel, represented by a channel matrix H represented by a singular value decomposition such that H = UΛV H, for unitary matrices U and V, and diagonal matrix Λ; an initialization module for deriving first and second components of the received information describing the transmission of the signal, wherein the first derived information component is UΛ and the second derived information component is V H, and for formatting the received signal for estimation by equalising a portion of the effect of transmission on the signal using the first derived component to generate a formatted signal comprising a plurality of formatted signal components; an error correction module for determining the plurality of estimated signal components from the predetermined alphabet which are closest to the formatted signal components in a space defined using the second derived information component; and an error detection module for receiving an estimation decision from the error correction module and determining whether the estimation decision contains one or more errors, the error detection module arranged to control the error correction module to correct an estimation decision error if one or more errors are determined, and to output a detected signal containing the estimated plurality of signal components if no error is determined; wherein the space defined using the second derived information component has M orthogonal dimensions, wherein the error correction module determines in parallel M estimated signal components by minimizing a sum of M linear distances in each of the M sub-spaces defined by the second derived information component between the estimated signal components and the formatted signal components for each of the M estimated signal components, assuming a fixed estimate for the other M-1 signal components. an input module for receiving a signal transmitted over a communications channel, the received signal comprising a plurality, M, of observed signal components from a predetermined alphabet, and the input module arranged to receive information describing the transmission of the signal over the communications channel, represented by a channel matrix H represented by a singular value decomposition such that H = UΛV H, for unitary matrices U and V, and diagonal matrix Λ; an initialization module for deriving first and second components of the received information describing the transmission of the signal, wherein the first derived information component is UΛ and the second derived information component is V H, and for formatting the received signal for estimation by equalising a portion of the effect of transmission on the signal using the first derived component to generate a formatted signal comprising a plurality of formatted signal components; an error correction module for determining the plurality of estimated signal components from the predetermined alphabet which are closest to the formatted signal components in a space defined using the second derived information component; and an error detection module for receiving an estimation decision from the error correction module and determining whether the estimation decision contains one or more errors, the error detection module arranged to control the error correction module to correct an estimation decision error if one or more errors are determined, and to output a detected signal containing the estimated plurality of signal components if no error is determined; wherein the space defined using the second derived information component has M orthogonal dimensions, wherein the error correction module determines in parallel M estimated signal components by minimizing a sum of M linear distances in each of the M sub-spaces defined by the second derived information component between the estimated signal components and the formatted signal components for each of the M estimated signal components, assuming a fixed estimate for the other M-1 signal components.