New multichannel fast QRD-LS adaptive algorithms

Two new fast multichannel QR decomposition (QRD) least squares (LS) adaptive algorithms are presented. Both algorithms deal with the general case of channels with different orders, comprise scalar operations only and are based on numerically robust orthogonal Givens rotations. The first algorithm is a block type scheme which processes all channels jointly. The second algorithm processes each channel separately and offers substantially reduced computational complexity compared to previously derived multichannel fast QRD schemes. This is demonstrated in the context of Volterra filtering