Design of a normalized delayless LMS adaptive subband digital filter

A new architecture is proposed for the normalized delayless least mean squares (NDLMS) adaptive subband filter. The proposed architecture is based on the hardware-efficient pipelined architecture for the LMS adaptive filter and subband methodology, and it can achieve good convergence characteristics, short latency and high throughput simultaneously without adaptation delays. In addition, it maintains the advantage of the normalised LMS, i.e., the step size assures that the convergence rate is determined automatically. Computer simulation results confirm that the proposed architecture achieves satisfied convergence rate identical to those of the normalised LMS in frequency-domain.