Feedback phase-shift compensation for adaptive interference cancellers

An algorithm typically used for adaptive co-site interference cancellers (f or frequency-hopping spread-spectrum communications systems) is the least-m ean-square error (LMS) algorithm. As adaptive cancellation moves into L-ban d and S-band, feedback system stability becomes a critical issue for co-sit e interference cancellers using the LMS algorithm. The authors present a te chnique for compensating the high-frequency feedback path phase shifts lead ing to instability with an additional complex weight multiplication at base band. Simulation and experimental results confirm the effectiveness of the technique.