536 research outputs found
Cooperative medium access control based on spectrum leasing
Based on cooperative spectrum leasing, a distributed “win–win” (WW) cooperative framework is designed to encourage the licensed source node (SN) to lease some part of its spectral resources to the unlicensed relay node (RN) for the sake of simultaneously improving the SN’s achievable rate and for reducing the energy consumption (EC). The potential candidate RNs carry out autonomous decisions concerning whether to contend for a cooperative transmission opportunity, which could dissipate some of their battery power, while conveying their traffic in light of their individual service requirements. Furthermore, a WW cooperative medium-access-control (MAC) protocol is designed to implement the proposed distributed WW cooperative framework. Simulation results demonstrate that our WW cooperative MAC protocol is capable of providing both substantial rate improvements and considerable energy savings for the cooperative spectrum leasing system
A Review- Proposed Bidirectional Relaying for Improved Channel Estimation Error and Co-Channel Interference
Wireless Communication has gained a lot of interest as future generation requires higher data rates and more suitable transmission with adequate quality of service. Wireless communication suffers from various problems like Co-Channel Interference (CCI) and Channel Estimation Error (CEE). Cooperative communication is an efficient technique to deal with these types of problems by offering significant multiplexing and diversity gains without increasing power and bandwidth. Our proposed two way relaying helps to improve the overall system performance in wireless networks. Cooperative communications also deals with the various problems like fading and shadowing. It is further investigated that proposed two way relaying is spectrally efficient technique which provides a way to surmount half duplexing loss in one way relay channel
Advanced DSP Algorithms For Modern Wireless Communication Transceivers
A higher network throughput, a minimized delay and reliable communications
are some of many goals that wireless communication standards, such as the fifthgeneration
(5G) standard and beyond, intend to guarantee for its customers. Hence,
many key innovations are currently being proposed and investigated by researchers in
the academic and industry circles to fulfill these goals. This dissertation investigates
some of the proposed techniques that aim at increasing the spectral efficiency, enhancing
the energy efficiency, and enabling low latency wireless communications systems.
The contributions lay in the evaluation of the performance of several proposed receiver
architectures as well as proposing novel digital signal processing (DSP) algorithms to
enhance the performance of radio transceivers. Particularly, the effects of several radio
frequency (RF) impairments on the functionality of a new class of wireless transceivers,
the full-duplex transceivers, are thoroughly investigated. These transceivers are then
designed to operate in a relaying scenario, where relay selection and beamforming
are applied in a relaying network to increase its spectral efficiency. The dissertation
then investigates the use of greedy algorithms in recovering orthogonal frequency
division multiplexing (OFDM) signals by using sparse equalizers, which carry out the
equalization in a more efficient manner when the low-complexity single tap OFDM
equalizer can no longer recover the received signal due to severe interferences. The
proposed sparse equalizers are shown to perform close to conventional optimal and
dense equalizers when the OFDM signals are impaired by interferences caused by the
insertion of an insufficient cyclic prefix and RF impairments
- …