Wendong Yang

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Cognitive radio (CR) is a promising technology to solve the challenging spectrum allocation problem. However, to implement CR, spectrum sensing is the groundwork and the precondition. In this paper, a fuzzy collaborative spectrum sensing scheme is proposed. The final sensing decision of the proposed scheme is based on the combination of distributed sensing(More)
We investigate physical-layer security (PLS) for multi-antenna and multi-relay networks with transmit beamforming and relay selection under feedback delay. The connection outage probability (COP) and secrecy outage probability (SOP) are derived to evaluate the reliability and security. Besides, we introduce a novel definition of the reliable-and-secure(More)
In this paper, a general framework of evaluating the joint effects of feedback delay and channel estimation errors (CEE) is formulated for two-hop amplify-and-forward (AF) relaying systems with transmit beamforming (TB) and relay selection. We derived closed-form expressions for important performance measures including the ergodic capacity, exact analysis(More)
In this paper, we propose a block-based selective orthogonal frequency division multiplexing (OFDM) decode-and-forward relaying scheme for 4G mobile communication systems. In the scheme, an OFDM symbol is divided into blocks and one relay is selected for each block. Theoretical outage performance and error performance are analyzed and evaluated. A unified(More)
We consider the channel estimation for two-way relay OFDM networks. We proposed an LS-based channel estimation algorithm under block-based training schemes. Based on the mean square error (MSE) criterion, the condition and the design method for optimal training sequences are discussed. To reduce peak-to-average power ratio (PAPR), a special sequence called(More)
Relay transmission can enhance coverage and throughput, whereas it can be vulnerable to eavesdropping attacks due to the additional transmission of the source message at the relay. Thus, whether or not one should use relay transmission for secure communication is an interesting and important problem. In this paper, we consider the transmission of a(More)
Analytically studying the overall outage performance of two-way amplify-and-forward (AF) relaying systems has always been a difficult task. In this paper we study the overall outage probability (OOP) for the two-way amplify-and-forward (AF) relaying system. The channels are independent but not identically Nakagami-m fading distributed. We obtain the tight(More)