Computationally efficient algorithm for reducing the complexity of software radio receiver's filter bank

In this paper, a computationally efficient method for extracting individual radio channels from the output of the wideband analog to digital converter (ADC) is presented. In a software radio, the extraction of individual channels from the output of the wideband ADC is by far the most computationally demanding task; hence it is very important to devise computationally efficient algorithms for this task. We proposed a new algorithm by assuming the symmetric signal with periods of the length-P (number of coefficients in low pass filter prototype) as an input signal to the subsampled filter bank. Also we divide the complex input x[n] into real and imaginary parts, then we perform operations in each part using two parallel filter banks. Finally, we add the outputs in two parts. By employing this algorithm to the subsampled filter bank channelizer, the complexity of the proposed algorithm was reduced by considerable amount of 81%.