A New Practical Receiver for a Decode-and-Forward Cooperative CDMA Systems Based on a Blind λ-Combiner

This paper develops a practical receiver suggested for cooperative systems using decode-and-forward transmission and compares it to the theoretical sub-optimum λ-MRC receiver model. The proposed receiver model adopts a channel blind λ-combiner and employs a practical estimation of the combiner's weight λ that changes adaptively for each received bit. The λ estimation process relies on a dynamic-blind calculation performed on the incoming bit stream using an approximate formula. The accuracy of the estimated values of λ against the numerical (optimum) values is verified by comparing their effects on the performance curves. Next, the performance of the proposed receiver is evaluated against the sub-optimum receiver using the closed-form performance equations then verified using an actual implementation of the decode-and-forward cooperative algorithm. The use of the proposed receiver is shown to have reliable performance under different channel assignments and provides adaptivity to channel variations without complexity or exaggerated signal processing.