This thesis is concerned with the data transmission over a mobile radio channel, which is characterized a by multipath propagation with a Rayleigh fading at 900 MHz, for different Doppler frequencies. The work introduces software radio receiver design and simulation. It then attempts to develop the software radio receiver over a mobile radio channel. Many techniques were used to improve the performance of the data transmission like equalization and diversity. An adaptive equalizer is used in this work to reduce the effect of intersymbol interference (ISI). Further enhancement is then achieved by using diversity. Space diversity is used here to combat with the Rayleigh fading effect, since it is the best combat for deep fading, where two and three antennas are used in this work. From the results it is clear that the system gives an advantage in tolerance to AWGN equal to 16 dB in case of using two-antenna diversity and equalize, but the advantages in tolerance to AWGN will increase in case of using threeantenna diversity and equalizer to about (24-25) dB over the case of detection without diversity and equalizer. Computer simulations have been carried out in Matlab 6.5 running on a Pentium IV personal computer for the software receiver and the data communication system. The results of such a simulation clearly demonstrate the performance of the software receiver. It also shows the enhancement in performance when equalization and diversity are used over the mobile radio channel