Area Efficient Fractional Sample Rate Conversion Architecture for Software Defined Radios

The modern software defined radios (SDRs) use complex signal processing algorithms to realize efficient wireless communication schemes. Several such algorithms require a specific symbol to sample ratio to be maintained. In this context the fractional rate converter (FRC) becomes a crucial block in the receiver part of SDR. The paper presents an area optimized dynamic FRC block, for low power SDR applications. The limitations of conventional cascaded interpolator and decimator architecture for FRC are also presented. Extending the SINC function interpolation based architecture; towards high area optimization and providing run time configuration with time register are presented. The area and speed analysis are carried with Xilinx FPGA synthesis tools. Only 15% area occupancy with maximum clock speed of 133 MHz are reported on Spartan-6 Lx45 Field Programmable Gate Array (FPGA).