Imbalance effects in spread-spectrum demodulation

Imperfections and parametric differences between the in-phase and quadrature channels in a communication receiver are of concern in designing a digital communications receiver. In the case of a spread-spectrum system, the effects on processing gain and symbol error rate performance are of interest. Since adaptive interference suppression (AIS) techniques may be employed, it is also of interest to study the effects of quadrature imbalance on their performance. The authors consider the effects of quadrature imbalance relative to these performance issues. Results are obtained by using analysis and simulation techniques. Initial results indicate that only small degradations are incurred from moderate quadrature imbalances