Network Coding (NC) brings correlation between the coded signals from different sources, which makes the system more vulnerable to the decode error at relay. Conventional Cyclic Redundancy Code (CRC) has been implemented for error bit detection. However, its error correction is simply ignored. To fully exploit this feature, this paper proposes a novel joint Log-Likelihood Ratio (LLR) CRC error mitigation for NC two way relay channel. Specific thresholds are designed to estimate the error number of data block and identify those which can be recovered if the number is within the error correction scope of CRC. We examine two modes of the thresholds, one based on the average Bit Error Rate (BER) of source-relay link, while the other based on that of instantaneous one. We provide the full analysis for the Pair-wise Error Probability (PEP) performance of the scheme. A variety of numerical results are presented to reveal the superiority of the proposed scheme to conventional CRC NC under independent Rayleigh fading channels. Moreover, the efficiencies of the proposed thresholds are also validated.
Multiple heterogeneous wireless techniques, possibly administered by different entities, are coexisted in the rapidly-expanding communications market. In order to understand the complex interactions among different network service providers（NSPs）, it is important to study the factors taken into consideration by users during their selections of the NSPs. The article focuses on interactions between macro-level dynamics of user subscription and the factors causing such dynamics. The key factor was discussed on the interactions between different subpopulations rather than the general factors such as quality of service（Qo S）. Guided by synergetic theory, a general mathematical description model was built. The influence of key factors on users＇ selections was considered and analyzed. Some examples were presented to validate capabilities of the proposed model.
