A block transmission method involving the use of time reversal and cyclic prefix and suffix

摘要

A block of information is processed before transmission thereof in a block transmission based communication (e.g. OFDM). This comprises inserting a cyclic prefix and a cyclic suffix into the block of information (fig. 14) before applying a time reversal based prefilter prior to transmission to the data, the prefilter being configured on the basis of knowledge of the condition of the channel over which communication is to be effected. At the receiver, a removal operation is operable to remove the effect of cyclic prefix and suffix insertion, the latter being removed from the head rather than the end of the block (fig. 14), leaving a circulant shifted version of the original block. This can be decoded using a diagonal matrix containing frequency domain channel coefficients on its diagonal entries after FFT. These are real-values coefficients, therefore, for systems with more than two transmit antennas, this facilities the use of full rate OSTBC (orthogonal space time block coding), regardless of whether real or complex signalling is transmitted.