Novel synchronous CDMA multiuser detection scheme: orthogonal decision-feedback detection and its performance study
X.H. Chen, H.K. Sim · IEE Proceedings - Communications · 1997
The authors propose a novel multiuser detection scheme for synchronous DS/CDMA systems, the orthogonal decision-feedback detector (ODFD), which performs equally well as the decorrelating decision-feedback detector (DDFD) but with a much reduced complexity. The ODFD employs a match filter bank matching to a set of orthonormal sequences which are generated by the Gram–Schmidt orthogonalisation procedure based on spreading codes. The ODFD algorithm involves only the orthonormal coefficient matrix which requires no frequent recalculations even when system parameters change. Successive decision-feedback detection is performed immediately at the output of the ODFD match filter bank without the transform matrix which is required in the DDFD.