Pilot assisted channel estimation technique for Alamouti STBC- MISO and MIMO Set-up with BPSK and QPSK modulation

The combination of coding with spatial diversity opens up new dimensions in wireless communications, and can offer effective solutions to the challenges faced in realizing reliable high-speed links. Use of Space-Time Block Coding (STBC) with Multiple-Input Multiple-Output (MIMO) set-up proves to be an efficient method for this task. In wireless environment there is no prior knowledge of the channel state information (CSI) and hence it is required to employ some estimation techniques to obtain an estimate of the channel. Channel estimation is thus an important step in receiver design. This paper proposes an estimation technique based on block type pilot symbols having an orthogonal nature for use in Space-Time Block Coding (STBC) with Multiple Antennas set-up for use in wireless channels. Results have been obtained for known channel case and pilot estimated channel information for two distinct modulation schemes, namely Binary Phase Shift Keying (BPSK) and Quadrature Phase Shift Keying (QPSK) respectively. The Bit Error Rate (BER) performance curves from the estimation technique show a result which is closely approaching the known channel case, proving its effectiveness.