Two reduced-complexity decoding algorithms for unitary space-time codes based on tree-structured constellation are presented. In this letter original unitary space-time constellation is divided into several groups. Ea...Two reduced-complexity decoding algorithms for unitary space-time codes based on tree-structured constellation are presented. In this letter original unitary space-time constellation is divided into several groups. Each one is treated as the leaf nodes set of a subtree. Choosing the unitary signals that represent each group as the roots of these subtrees generates a tree-structured constellation. The proposed tree search decoder decides to which sub tree the receive signal belongs by searching in the set of subtree roots. The final decision is made after a local search in the leaf nodes set of the se-lected sub tree. The adjacent subtree joint decoder performs joint search in the selected sub tree and its “surrounding” subtrees,which improves the Bit Error Rate (BER) performance of purely tree search method. The exhaustively search in the whole constellation is avoided in our proposed decoding al-gorithms,a lower complexity is obtained compared to that of Maximum Likelihood (ML) decoding. Simulation results have also been provided to demonstrate the feasibility of these new methods.展开更多
In this paper,a Joint Early Detection and Early Stopping (JEDES) approach for effectively reducing the complexity of turbo decoding with negligible performance loss is proposed. It combines the effectiveness of both e...In this paper,a Joint Early Detection and Early Stopping (JEDES) approach for effectively reducing the complexity of turbo decoding with negligible performance loss is proposed. It combines the effectiveness of both early detection and early stopping techniques. Our simulation results demon-strated that the proposed JEDES scheme based on cyclic redundancy check and trellis splicing can achieve a complexity saving of 15% to 20% at practical bit error rates over the idealized GENIE stopping scheme,which is widely accepted as the theoretically best possible early stopping scheme.展开更多
基金Supported by the National Natural Science Foundation of China (No.60572148).
文摘Two reduced-complexity decoding algorithms for unitary space-time codes based on tree-structured constellation are presented. In this letter original unitary space-time constellation is divided into several groups. Each one is treated as the leaf nodes set of a subtree. Choosing the unitary signals that represent each group as the roots of these subtrees generates a tree-structured constellation. The proposed tree search decoder decides to which sub tree the receive signal belongs by searching in the set of subtree roots. The final decision is made after a local search in the leaf nodes set of the se-lected sub tree. The adjacent subtree joint decoder performs joint search in the selected sub tree and its “surrounding” subtrees,which improves the Bit Error Rate (BER) performance of purely tree search method. The exhaustively search in the whole constellation is avoided in our proposed decoding al-gorithms,a lower complexity is obtained compared to that of Maximum Likelihood (ML) decoding. Simulation results have also been provided to demonstrate the feasibility of these new methods.
基金the National Natural Science Foundation of China (NSFC)the Research Grants Council of Hong Kong (RGC) joint research scheme (No.60218001/N_ HKUST617-02 and No.60272070).
文摘In this paper,a Joint Early Detection and Early Stopping (JEDES) approach for effectively reducing the complexity of turbo decoding with negligible performance loss is proposed. It combines the effectiveness of both early detection and early stopping techniques. Our simulation results demon-strated that the proposed JEDES scheme based on cyclic redundancy check and trellis splicing can achieve a complexity saving of 15% to 20% at practical bit error rates over the idealized GENIE stopping scheme,which is widely accepted as the theoretically best possible early stopping scheme.
