1. A modulator comprising: a symbol mapper configured to receive a bit sequence corresponding to a radio burst and comprising data bits, training bits, tail bits and guard bits and to map respective sets of at least one bit of said bit sequence into respective symbols to form a symbol sequence comprising data symbols, training symbols, tail symbols and guard symbols; a vector precoder configured to apply a vector precoding transformation to said data symbols and said training symbols without applying the vector precoding transformation to said tail symbols and said guard symbols to form corresponding precoded symbols of said data symbols and said training symbols; a processor configured to add one of a prefix and a postfix to the precoded symbols; and a symbol processor configured to form a sequence of transmit symbols comprising said tail symbols and said guard symbols from said symbol mapper and said precoded symbols from said vector precoder.