A method for detecting information bits in a received signal y, said received signal comprising a superposition of at least a first signal x 0, a second signal x 1 and additive noise n with power σ n 2 such that y = h 0 · x 0 + h 1 · x 1 + n with appropriate weights h 0 and h 1, said method comprising the steps of: computing, from the received signal, first log-likelihood ratios for codebits represented by the first signal; computing, from the received signal and the first log-likelihood ratios, second log-likelihood ratios for codebits represented by the second signal; and decoding the codebits represented by the second signal on the basis of the computed second log-likelihood ratios, characterized in that the first log-likelihood ratios for the first signal are computed according to an equation equivalent to L 1 st c i = log ∑ x 0 ∈ A 1 st, i 0 exp − 1 σ ̃ 2 ‖ y − h 0 x 0 ‖ 2 ∑ x 0 ∈ A 1 st, j 1 exp − 1 σ ̃ 2 ‖ y − h 0 x 0 ‖ 2, or L 1 st c i = log ∑ x 0 ∈ A 1 st, i 0 ∑ x 1 ∈ A 2 nd exp − 1 σ n 2 ‖ y − h 0 x 0 − h 1 x 1 ‖ 2 ∑ x 0 ∈ A 1 st, i 1 ∑ x 1 ∈ A 2 nd exp − 1 σ n 2 ‖ y − h 0 x 0 − h 1 x 1 ‖ 2, with i = 0..log 2 |A 1 st | - 1, and the second log-likelihood ratios for the second signal are computed according to an equation equivalent to L 2 nd c j = log ∑ x 0 ∈ A 1 st ∑ x 1 ∈ A 2 nd, j 0 exp − 1 σ 2 ‖ y − h 0 x 0 − h 1 x 1 ‖ 2 − ∑ i = 0 log 2 A 1 st − 1 μ i − 1 x 0 L 1 st c i ∑ x 0 ∈ A 1 st ∑ x 1 ∈ A 2 nd, j 1 exp − 1 σ 2 ‖ y − h 0 x 0 − h 1 x 1 ‖ 2 − ∑ i = 0 log 2 A 1 st − 1 μ i − 1 x 0 L 1 st c i, with j = 0..log 2 | A 2 nd | - 1, wherein L 1 st ( c i) denotes the log-likelihood ratio for the i -th codebit c i for each bit-level i with 0 ≤ i < log 2 |A 1 st |, L 2 nd ( c j) denotes the log-likelihood ratio for the j -th codebit c j for each bit-level j with 0 ≤ j < log 2 | A 2 nd |, A 1 st is the symbol alphabet for the first layer, A 1 st, i b are the first-layer sub-alphabets for which the i -th codebit c i assumes the binary value b = {0,1}, A 2 nd is the symbol alphabet for the second layer, A 2 nd, j b are the second-layer sub-alphabets for which the j -th codebit c j assumes the binary value b = {0,1}, μ i -1 (x 0) is an inverse mapping function which takes a symbol from the first layer, x 0, and returns the i-th codebit carried by this symbol, and σ ̃ 2 = h 1 2 ⋅ E x 1 2 + σ n 2 is the equivalent noise power. computing, from the received signal, first log-likelihood ratios for codebits represented by the first signal; computing, from the received signal and the first log-likelihood ratios, second log-likelihood ratios for codebits represented by the second signal; and decoding the codebits represented by the second signal on the basis of the computed second log-likelihood ratios, characterized in that the first log-likelihood ratios for the first signal are computed according to an equation equivalent to L 1 st c i = log ∑ x 0 ∈ A 1 st, i 0 exp − 1 σ ̃ 2 ‖ y − h 0 x 0 ‖ 2 ∑ x 0 ∈ A 1 st, j 1 exp − 1 σ ̃ 2 ‖ y − h 0 x 0 ‖ 2, or L 1 st c i = log ∑ x 0 ∈ A 1 st, i 0 ∑ x 1 ∈ A 2 nd exp − 1 σ n 2 ‖ y − h 0 x 0 − h 1 x 1 ‖ 2 ∑ x 0 ∈ A 1 st, i 1 ∑ x 1 ∈ A 2 nd exp − 1 σ n 2 ‖ y − h 0 x 0 − h 1 x 1 ‖ 2, with i = 0..log 2 |A 1 st | - 1, and the second log-likelihood ratios for the second signal are computed according to an equation equivalent to L 2 nd c j = log ∑ x 0 ∈ A 1 st ∑ x 1 ∈ A 2 nd, j 0 exp − 1 σ 2 ‖ y − h 0 x 0 − h 1 x 1 ‖ 2 − ∑ i = 0 log 2 A 1 st − 1 μ i − 1 x 0 L 1 st c i ∑ x 0 ∈ A 1 st ∑ x 1 ∈ A 2 nd, j 1 exp − 1 σ 2 ‖ y − h 0 x 0 − h 1 x 1 ‖ 2 − ∑ i = 0 log 2 A 1 st − 1 μ i − 1 x 0 L 1 st c i, with j = 0..log 2 | A 2 nd | - 1, wherein L 1 st ( c i) denotes the log-likelihood ratio for the i -th codebit c i for each bit-level i with 0 ≤ i < log 2 |A 1 st |, L 2 nd ( c j) denotes the log-likelihood ratio for the j -th codebit c j for each bit-level j with 0 ≤ j < log 2 | A 2 nd |, A 1 st is the symbol alphabet for the first layer, A 1 st, i b are the first-layer sub-alphabets for which the i -th codebit c i assumes the binary value b = {0,1}, A 2 nd is the symbol alphabet for the second layer, A 2 nd, j b are the second-layer sub-alphabets for which the j -th codebit c j assumes the binary value b = {0,1}, μ i -1 (x 0) is an inverse mapping function which takes a symbol from the first layer, x 0, and returns the i-th codebit carried by this symbol, and σ ̃ 2 = h 1 2 ⋅ E x 1 2 + σ n 2 is the equivalent noise power. L 1 st ( c i) denotes the log-likelihood ratio for the i -th codebit c i for each bit-level i with 0 ≤ i < log 2 |A 1 st |, L 2 nd ( c j) denotes the log-likelihood ratio for the j -th codebit c j for each bit-level j with 0 ≤ j < log 2 | A 2 nd |, A 1 st is the symbol alphabet for the first layer, A 1 st, i b are the first-layer sub-alphabets for which the i -th codebit c i assumes the binary value b = {0,1}, A 2 nd is the symbol alphabet for the second layer, A 2 nd, j b are the second-layer sub-alphabets for which the j -th codebit c j assumes the binary value b = {0,1}, μ i -1 (x 0) is an inverse mapping function which takes a symbol from the first layer, x 0, and returns the i-th codebit carried by this symbol, and σ ̃ 2 = h 1 2 ⋅ E x 1 2 + σ n 2 is the equivalent noise power.