Dongfeng Yuan

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The fourth generation wireless communication systems have been deployed or are soon to be deployed in many countries. However, with an explosion of wireless mobile devices and services, there are still some challenges that cannot be accommodated even by 4G, such as the spectrum crisis and high energy consumption. Wireless system designers have been facing(More)
To improve power efficiency in vehicle-to-roadside infrastructure (V2I) communication networks, this paper proposes a joint power and sub-carrier assignment policy under delay aware quality of service (QoS) requirements. Due to the real-time nature of the V2I transmissions, the proposed policy should satisfy delay aware QoS requirements with a minimized(More)
The knowledge of channel statistics can be very helpful in making sound opportunistic spectrum access decisions. It is therefore desirable to be able to efficiently and accurately estimate channel statistics. In this paper, we study the problem of optimally placing sensing/sampling times over a time window so as to get the best estimate of the parameters of(More)
Multi-hop structure and broadcast channel of wireless sensor networks necessitate error control schemes to achieve reliable data transmission. The energy efficiency of error control schemes should be considered because of the strict energy constraints of wireless sensor networks. Wireless sensor networks require simple and facile error control schemes(More)
In this paper, we propose a new concept called mobile Femtocell (MFemtocell) network, which can be considered as a practical implementation of mobile relays (more precisely, moving networks). MFemtocells can be deployed in moving vehicles, such as trains, buses, or private cars to provide enhanced user throughput, extended coverage, and reduction of the(More)
Artificial Fish Swarm Algorithm (AFSA) is a novel intelligent optimization algorithm. It has many advantages, such as good robustness, global search ability, tolerance of parameter setting, and it is also proved to be insensitive to initial values. However, it has some weaknesses as low optimizing precision and low convergence speed in the later period of(More)
The problem of optimal resource allocation to share high-quality multimedia content in cognitive ad hoc networks with cooperative relays is addressed in this paper. Cooperative transmission is a promising technique to increase the capacity of wireless links by exploiting spatial diversity without multiple antennas at each node. However, mainstream research(More)
This paper proposes a novel power control policy for a cognitive radio network as an effort to maximize throughput under the average interference power constraint. The underlined policy ensures delay-related quality of service (QoS) requirements with reduced interference to the primary user. In this work we also take into account the peak and average(More)
Multiuser orthogonal frequency division multiplexing (MU-OFDM) is a promising technique for achieving high downlink capacities in future cellular and wireless local area network systems. The capacity of MU-OFDM can be maximized as long as subchannels and power are allocated adaptively, a new method based on genetic algorithm (GA) is proposed for adaptive(More)