DSP implementation of a wideband frequency selective fading simulator

The design and implementation of a wideband digital frequency selective fading simulator is presented. The system is modular with each module catering for one delayed faded signal path. The multipath delay is variable between 0 and 204 microseconds. Associated with each path is a complex Gaussian noise source which is implemented on a TMS320-20 digital signal processor. The power spectra and the cross power spectra of the complex noise may be set by the user. The Doppler shift range is 0 to 300 Hz. The dynamic range of the simulator is 40 dB and each signal path may be attenuated within this range to form the required power delay profile. The mean signal strength can be modulated by a lognormal process is simulate slow fading. The bandwidth is 5 MHz. The simulator accepts an RF input an provides and RF output. The simulator configuration is completely under the control of a personal computer