Method and receiver for jointly decoding received communication signals using maximum likelihood detection

A method in a receiver for decoding at least two received communication signals, said communication signals being modulated, pre-coded by a discrete Fourier transform and transmitted by a single-carrier frequency division multiple access scheme (SC-FDMA), said method comprising the steps of:

• performing antenna combining and equalization on a signal Y(m) observed at said receiver based on a weighting matrix W(m) to provide a model of observed signal {circumflex over (X)}(m) and a frequency domain channel estimate {tilde over (H)}(m);
• performing inverse discrete Fourier transform on said model of observed signal {circumflex over (X)}(m) to provide a time domain model {tilde over (S)}(n) of said observed signal {circumflex over (X)}(m);
• performing an inverse discrete Fourier transform of said frequency domain channel estimate {tilde over (H)}(m) to provide a time domain channel estimate {tilde over (G)}(p) with length P wherein p=0, 1, . . . , P−1;
• whitening said time domain model {tilde over (S)}(n) of said observed signal {circumflex over (X)}(m) to provide a whitened time domain model Ŝ(n) of said time domain model {tilde over (S)}(n) and a whitened time domain channel estimate Ĝ(p) for p=0, 1, . . . , P−1, wherein the whitening of said time domain model is performed after performing the antenna combining and equalization step and after performing the inverse discrete Fourier transform on the model of the observed signal;
• and
• jointly detecting said received at least two communication signals by performing soft value calculations based on maximum likelihood detection (MLD) of said whitened time domain model Ŝ(n) and by using said whitened time domain channel estimate Ĝ(p) for p=0, 1, . . . , P−1, wherein the joint detection decodes said at least two received communication signals.