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Cognitive radio (CR) as one of the most promising technologies to solve the problem of exhausting of spectrum resource, draws a lot of attention recently. However, for the highly intelligent wireless devices in the future, the assumption "CR devices introduce no interference to the primary users (PUs)" in traditional CR systems may do not exist anymore, due(More)
The resource allocation and limited feedback scheme are proposed in multiuser MIMO OFDM systems. The optimization model is to maximize the throughput with minimal and maximal transmit rate constraint of users, which can effectively guarantees the QoS requirment of multimedia traffics. The resource allocation is divided into user selection and power(More)
The 3rd generation partnership project (3GPP) long term evolution (LTE) standard has adopted orthogonal frequency division multiplexing access (OFDMA) in downlink and single carrier-frequency division multiple access (SC-FDMA) scheme for the uplink transmissions, which utilizes single carrier modulation and frequency domain equalization. In this paper, we(More)
—In this paper, for multiuser MIMO system, we consider a suboptimal scheduling scheme that allocates the channel to the user whose channel matrix has the maximal Frobenius norm and also we derive a tight expression of system capacity for it. Furthermore, exploiting this Frobenius norm, we propose a threshold based limited feedback scheme and give a(More)
— Spectrum pooling, which allows the secondary networks to utilize the available spectrum bands from different licensed networks, is one of the most promising technologies for dynamic spectrum sharing in cognitive radio systems. Most previous work on spectrum pooling concentrates on the system architecture and the design of flexible access algorithms and(More)