Symbols are encoded in a transmitter of a wireless network that uses multiple-input and multiple-output (MIMO) orthogonal frequency division multiplexing (MIMO-OFDM) by partitioning the sub-carriers to be used for transmitting the symbol into a set of K groups of contiguous sub-carriers. For each group k of NK−1 modulation symbols Dk(1), Dk(2), Dk(NK−1), the modulation symbol Dk(n), for group k, is mapped to a corresponding mapped modulation symbols Xk(n) according to m  ( k ) = 1 N K - 1  ∑ n = 1 N K - 1   D k  ( n ) , Xk(n)=α1(k)(Dk(n)−m(k))+βk) n=1, . . . , NK−1, Xk(NK)=α2(k)m(k), where m(k) is a sample-mean of the set of modulation symbols corresponding to the kth group, α1 (k), α2 (k) and β(k), for k=1, . . . , K, are constants, wherein the constants are predetermined and positive.