DESIGN AND DEVELOPMENT OF A MULTIRATE FILTERS IN SOFTWARE DEFINED RADIO ENVIRONMENT
L. C Loong, Ng Chee Kyun, Cao Hui, Nor Kamariah Noordin · 2008
Many well-known digital signal processing (DSP) technologies have been developed for communications, speech processing, radar and sonar systems. One of the basic elements in DSP is sampling rate. Many different sampling rates are used in digital communication applications. Software defined radio (SDR) concept is one of the techniques used to comply with any sampling rate, within a wide range of rates, in order to be compatible with many current protocols. This paper present the multirate filters design using SDR concept. Two SDR models are considered; one with System Generator and one which was absed on Matlab Simulink. The model of System Generator employs sampling rate concept, while the model of without utilizing System Generator employs multirate filter concept. Both models are developed and simulated to produce the desired audio sampling rate for comparison. In the sampling rate concept, a general filter is used to increase and decease the input rate from continuous signal to discrete signal. In contrast, the multirate filter concept uses decimator and interpolator to increase and decrease the input rate respectively. The results show that both models can produce the desired audio sample rate. The later model produces the output faster than the former model but cannot generate Very High Description Language (VHDL) codes. The present of System Generator in Simulink software is to generate the VHDL codes in order to produce a Bit file that can be uploaded to Xilinx FPGA XSV-300 board. Finally, the audio wave file is played from Xilinx FPGA XSV-300 board.