Eigenvalue Spread based Improved VSSALMS Algorithm for Antenna Beamforming using Digital Signal Processor

In this paper, a well-researched existing Variable Step Size Adaptive LMS algorithms (VSSALMS) have been investigated in the light of larger eigenvalue spread of input process to bring faster convergence followed by better steady state response. As a result an improved VSSALMS has been developed for antenna beamforming and tested by implementing through a Digital Signal Processor (DSP) kit TMS320VC5416. The novelty of the improved VSSALMS algorithm includes consideration of large eigenvalue spread of the input process along with an exponentiation factor in the step size adaptation formula for about 45% faster convergence at 30dB SNR condition. Analysis under zero mean unit variance white Gaussian input followed by large eigenvalue spread filtered input process confirms its superiority in respect of convergence speed, tracking ability and steady state performance over earlier algorithms. The improved VSSALMS algorithm has been utilized for antenna beamforming using DSP with the capability of multiple interference cancellation with large attenuation compared to other existing VSSALNIS algorithms. Simulation results have been included to justify the improvement.