Multiple Steiner codes are transmitted as bursts from multiple base stations (182, 184, 186) having one or more transmit elements (174, 176, 178, 180), with successive bursts providing an extended training sequence for use in channel
estimation at an addressed unit (172), such as a mobile
handset. Accurate channel
estimation is possible through the use of Wiener
frequency domain MMSE
deconvolution (518) combined with
frequency domain spatial decoupling matrices, with quasi-orthogonal pseudo-
noise sequences (502, 504, 520, 522) allocated to base stations and their antenna elements. The use of Steiner codes to supplement Wiener
frequency domain MMSE
deconvolution and frequency domain spatial decoupling results in the possibility of allocating only a single training sequence to each
base station provided that the training sequence is of sufficient length to encompass all multiple time-translated channel impulse responses (H). Estimates may be refined iteratively by minimising the MS error of demodulated
pilot symbols. Estimates may also be refined by removing taps from the
impulse response which are insignificant based on a relatively long-term power-
delay profile for the channel.