An Efficient Space-time Coding for Wireless Communications with Offset 4 - Phase Shift Keying

Channel capacity has long been a block in wireless communications. Various approaches are present in the literatures which are very effective in enhancing signal reception quality in fading channels. Various multiple antenna approaches have been used in wireless communications to combat the fading effect, which enhances both the channel capacity and performance greatly. Transmit Antenna Selection (TAS) is a well-known approach to improve diversity in multi-input multi-output (MIMO) communications. But the main drawback of TAS is that, it is very sensitive to feedback errors. Hence, Space-Time Coding (STC) is a communication approach for wireless systems that inhabit multiple transmit antennas and single or multiple receives antennas. In this paper, Space-Time Coding (STC) is employed in MIMO signaling scheme which helps in providing better knowledge at the receiver and no knowledge at the transmitter. Spacetime trellis codes, space-time block codes and space-time differential coding are the STCs used in this paper. In this approach, the performance of the STC code is improved by the proposed Extended Balanced Space-Time Block Codes (EBSTBC). Also, this paper uses Offset 4Phase-Shift Keying (O4-PSK) instead of 4Phase-Shift Keying (4-PSK). This will help in reducing the bit error rate. The experiment is done with different PSK and with different bit rates. When the frame error probability is evaluated, the proposed EBSTBC system shows lesser error probability when compared to the previous STC codes.