Patent Document ID: 20120051475
Application ID: 12869875
Patent Flag: 0

Claim One:
1. A QR-RLS adaptive digital filter having N taps, the QR-RLS adaptive digital filter comprising: a D-machine which is capable of calculating the product of a PL-matrix and an input stream using 18-bit integer multipliers, the PL-matrix being a square matrix of dimensions N×N; a G-machine which is capable of calculating the inverse square root of a gain factor gamma, the G-machine including a floating point block which changes the scale of the inverse square root based on an input signal level so as to adjust the dynamic range of the inverse square root calculation; a Q-machine which is capable of applying matrix rotations and manipulations calculated by the G-machine to PL-matrix data using 18-bit integer multipliers; A W-machine which is capable of calculating filter taps and applying a digital filter to the input data stream using 18-bit integer multipliers according to parameters supplied by the Q-machine; An L-machine which is capable of calculating a forgetting factor lambda and applying it to parameters supplied by the Q-machine so as to calculate an adapted PL-matrix; and a P-memory capable of storing a D-copy of the PL-matrix and a Q-copy of the PL-matrix, the Q-copy being supplied to the Q-machine in sequential rows and columns without column offsets, the D-copy being supplied to the D-machine in sequential rows and columns with column offsets, the column offsets being determined according to the relative clocking speeds of the P-memory and the D-machine so as to optimize pipeline processing efficiency of the QR-RLS filter.