We are going to implement and study a space frequency coded OFDM system which consists of two transmitters and a single receiver. Simple Alamouti spacetime code is used. An M-ary PSK modulation is used to modulate the symbols across an OFDM channel. We will also propose a variation of the scheme which tries to spread additional symbols across time-frequency attempting to increase the rate of transmission without changing the type of modulation employed or increasing bandwidth. A Rayleigh frequency selective slow fading channel is assumed throughout the analysis. SER performance of the above systems is carried-out with emphasis on the modulation scheme, no. of carriers and bit SNR.
Space time coding, OFDM, frequency-selective channel
