Implementation of a Smart Antenna System on a General-Purpose Digital Signal Processor Utilizing a Linearized CGM
Seungwon Choi, Hong-Min Son, Tapan K. Sarkar · Digital Signal Processing · 1997
The objective is to present a practical method of implementing a beamforming module with a general-purpose digital signal processor. The proposed module provides a beam-pattern that has its maximum gain along the direction of a target mobile subscriber using real-time processing. The new technique utilizes a modified CGM (conjugate gradient method) in such a way that the suboptimal gain vector of the array is obtained from the solution of an eigenvalue problem. The solution is carried out at every snapshot upon the arrival of a new signal vector. By decomposition at the autocorrelation matrix of the array inputs, the computational load of the conventional CGM, i.e.,O(3N2 + 12N), has been reduced significantly to the order ofO(16N) in the proposed technique, whereNdenotes the number of antenna elements of the array. The performance of the proposed system is evaluated utilizing three different criteria; first, the execution speed for the implemented beam-former to trace the target subscriber; second, the BER (bit error rate) as a function of a given signal-to-noise ratio; and finally, the achievable capacity of the cell as a function of required BER.