Software Defined Adaptive Codec for Cognitive Radio

Recently, Cognitive Radio has been proposed as a promising technology to improve spectrum utilization. A highly flexible SDR (Software defined Radio) system needs to configure each of its blocks to give optimum performance over the available bandwidth. Present work discusses an approach for software defined adaptive coder yielding minimum BER (Bit error rate) for emergency services over cognitive radio. The results verify the efficiency of the algorithm which configures the convolution encoder to produce a lower BER for increased Bandwidth available. This can be readily implemented in the SDR library functions. This has been tested by FPGA implementation of the convolution encoder using Matlab HDL coder. The coder output of the FPGA implemented VHDL code has also been presented. Various WiMax Systems to be included in the SDR Library are puttforth. SDR adapts to the best suitable design, yielding lower BER in available channel conditions. Key-Words: Cognitive Radio, SDR library, Rate Adaptive Coder, BER, FPGA implementation.