A Spectrally Efficient Transmission Scheme for Half-Duplex Decode-and-Forward Relaying

Relying has in use for decades to tackle some of the challenges of wireless communication such as extending transmitting distance, transmitting over rough terrains. Diversity achieved through relaying is also a means to combat the random behavior of fading channels. In this work, effect of time and power allocation on relay performance is studied. The channel considered is the three-node channel with half-duplex constraint on the relay. The relaying technique assumed is decode-and-forward. Mutual information is used as the criteria to measure channel performance. There is half-duplex constraint and a total transmission power constraint on the relay source node and the relay node. A model is established to analyze the mutual information as a function of time allocation and power allocation in the case of AWGN regime. The model is extended to the Rayleigh fading scenario. In both AWGN and Rayleigh fading, results showed that the importance of relaying is more apparent when more resources are allocated to the relay. It was also shown that quality of the source to destination link has direct impact on the decision to relay or not to relay. Relatively good source to destination channel makes relaying less useful. The opposite is true for the other two links, namely the source to relay channel and the relay to destination channel. When these two channels are good, relaying becomes advantageous. When applied to cellular systems, we concluded that relaying is more beneficial to battery-operated mobile nodes than to base stations.

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An energy-efficient transmission scheme for monitoring of combat soldier health in tactical mobile ad hoc networks

MILCOM 2012 - 2012 IEEE Military Communications Conference ◽

10.1109/milcom.2012.6415827 ◽

2012 ◽

Author(s):

Emeka E. Egbogah ◽

Abraham O. Fapojuwo ◽

Liqi Shi

Keyword(s):

Ad Hoc Networks ◽

Mobile Ad Hoc Networks ◽

Energy Efficient ◽

Ad Hoc ◽

Transmission Scheme ◽

Combat Soldier ◽

Mobile Ad Hoc ◽

Hoc Networks ◽

Efficient Transmission

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1b/s/Hz spectrally efficient transmission for an 8 channel RZ modulated DWDM systems

Proceedings of The 2014 International Conference on Control, Instrumentation, Energy and Communication (CIEC) ◽

10.1109/ciec.2014.6959142 ◽

2014 ◽

Cited By ~ 1

Author(s):

Robin Vij ◽

Neeraj Sharma

Keyword(s):

Spectrally Efficient ◽

Efficient Transmission

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An Improved Simplified-CE Stopping Criterion for BICM-ID System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.846-847.1262 ◽

2013 ◽

Vol 846-847 ◽

pp. 1262-1265

Author(s):

Miao Miao Li ◽

Jian Ping Li

Keyword(s):

Iterative Decoding ◽

Rayleigh Fading ◽

Signal To Noise Ratio ◽

Coded Modulation ◽

Cross Entropy ◽

Stopping Criterion ◽

Transmission Scheme ◽

Stopping Criteria ◽

Bit Interleaved Coded Modulation ◽

Efficient Transmission

Bit-interleaved coded modulation iterative decoding (BICM-ID) is an excellent bandwidth efficient transmission scheme,which owns remarkable bit-error-rate (BER) performance both in additive Gaussian noise (AWGN) channel and Rayleigh fading channel.But it leads to the increase of computational complexity and decoding delay at the receiver at the same time. In order to decrease the unnecessary iterations ,a variety of the stopping criteria are put forward . This paper presents an improved simplified cross-entropy (CE) stopping criterion based on Simplified-CE criterion, which calculates the value of CE just one time when Signal to Noise Ratio (SNR) is under 2dB to simplified the iterative process. Simulation results show that the improved Simplified-CE criterion can own the least iterative number when the SNR is under 2dB.And when the SNR is from 2.5dB to 4dB, it is about 12% less than CE criterion in the average iterative numbers.

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