A high-rate transmit diversity technique for wireless communication

The increasing demand for higher data rates and higher quality in wireless communications has motivated the use of multiple antenna elements. MISO (Multiple Input Single Output) is an antenna technology for wireless communications in which multiple antennas are used at the source (transmitter) and single antenna used at receiver. Multiple transmitting antenna system improves the channel gain with same power and bandwidth requirement. A Maximum diversity of such an system can be obtained by exploiting the Space Time Block Codes. Some of Space Time Block Codes that can achieve full diversity for an MISO system are Toeplitz STBC, Overlapped Alamouti STBC, Alamouti-Toeplitz STBC. Though achieving full diversity in MISO system is quite complicated, STBC schemes can achieve maximum diversity by using Linear Receivers. This paper proposes an Orthogonal Frequency Division Multiplexing (OFDM) on both the transmitter and receiver to enhance the data rate and to eliminate the interference. Also this paper focuses on the bit error performance analysis of the various STBC schemes that incorporates OFDM for a Square Quadrature Amplitude Modulation (QAM) constellation using Zero Forcing (ZF) receiver.