A Novel Blind Subspace Code-Aided Rejection of Narrowband Interference in CDMA Systems - Part II: Adaptive Implementation

A blind adaptive subspace code-aided technique for suppression of narrowband interference (NBI) and multiple access interference (MAI) in code division multiple access (CDMA) networks is proposed. This technique is based on projection approximation subspace tracking with deflation (PASTd) algorithm to improve the performance of recursive least square (RLS) algorithm based on direct matrix inverse (DMI) code-aided technique. Specifically, the performance of this technique against the type of NBI, namely, quasi-deterministic signals including sinusoidal tones and data NBI is analyzed. In this paper, signal to noise and interference rate (SINR) performance against NBI and MAI is compared with DMI RLS algorithm. It is seen that this method outperforms current DMI RLS technique.