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—The voice-over-Internet protocol (VoIP) has attracted a great deal of attention in the field of wireless mobile networks. In this paper, we propose an improved ertPS scheduling algorithm for VoIP services in IEEE Std 802.16e system. It can solve both the problems waste of uplink resources caused by the UGS algorithm as well as MAC overhead and access delay(More)
We have studied the space-time trellis code (STTC) design in OFDM systems. By the research, especially by simulation, it is shown that, in multi-flat fading channels, the STTC-OFDM system can potentially provide more coding gain. We also found that the optimal STTC design is important for OFDM when using space-time codes (STC). By following this conclusion,(More)
In this paper, compressed sensing (CS) theory is utilized in a medium-access control (MAC) scheme for wireless sensor networks (WSNs). We propose a new, cross-layer compressed sensing medium-access control (CL CS-MAC) scheme, combining the physical layer and data link layer, where the wireless transmission in physical layer is considered as a compress(More)
Moir´e artifacts are generally caused by the interference between the overlap of the sensor's sampling grid and high-frequency (nearly) periodic textures, and heavily affect the image quality. However, it is difficult to effectively remove moir´e artifacts from textured images as the structure of moir´e patterns is similar to that of textures in some sense.(More)
A new kind of encoding as well as a linear differential decoding method is proposed in this article. A new model built in the TWRC (two-way relay channels) is presented, which involves partial response coding at the source and two different kinds of differential coding(the add-differential coding and the multiple-differential coding) at the relay. This(More)
Physical layer security is an attractive security mechanism, which exploits the randomness characteristics of wireless transmission channel to achieve security. However, it is hampered by the limitation of the channel condition that the main channel must be better than the eavesdropper channel. To alleviate the limitation, cooperative communication is(More)
Moiré artifacts are generally caused by the interference between the overlap of the sensor’s sampling grid and high-frequency (nearly) periodic textures, and heavily affect the image quality. However, it is difficult to effectively remove moiré artifacts from textured images as the structure of moiré patterns is similar to that(More)
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