A Performance Study of Dual-Hop Transmissions With Fixed Gain Relays

The use of multiple antennas in two-hop amplify-and-forward relay selection is analysed, where the source, relay and destination are each equipped with multiple receive but single transmit antennas. Since relay switching is based upon fed back information which is delay-limited, channel power prediction is employed to mitigate against the effect of outdated channel state information being used to make switching decisions. During transmission, a source selects a best relay on the basis of predicted SNR (signal to noise ratio) over all available links. A chosen relay then employs maximal ratio combining at its receiver, and applies a variable gain to the received signal before forwarding to the destination. Closed form outage probability and bit error rate solutions are found for arbitrary numbers of relays and receive antennas, and used to explore trade offs between number of relays and number of antennas compared to single antenna alternatives. To assess predictor performance in combatting switching delay, comparison is made to non-predictive systems.

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“…After simplification of (5) [20], the equivalent SNR at MD can then be calculated as γeq = γ 1 γ 2 γ 1 +γ 2 +1 with…”

Section: System Model and Assumptionsmentioning

confidence: 99%

Channel prediction in non-regenerative multi-antenna relay selection systems

Prakash

McLoughlin

2012

IET Communications

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“…The ability of relay R to generate the appropriate gain, depending on the fading conditions in both hops, leads to an end-to-end SNR, which using (4) with (6) and (7) is formulated as where yi is the instantaneous SNR of the ith hop, following the exponential PDF defined as Note that, as mentioned in Section 1, the performance analysis of dual-hop systems with relay given by (6) has been extensively studied in the literature [I], 131, [4], [5], [7]. Thus, in the following, only the case of g = g2 will be further studied.…”

Section: Mode Of Operationmentioning

confidence: 99%

“…Looking through the recent up-to-date open technical literature, the performance of dual-hop wireless communication systems are studied in [I], [4], [5], [6], [7]. Hasna and Alouini have presented a useful and semi-analytical framework for the evaluation of the end-to-end outage probability of multihop wireless systems with non-regenerative channel state information (CS1)-assisted relays over Nakagami-m fading channels [I].…”

Section: Introductionmentioning

confidence: 99%

“…This bound corresponds to an ideal relay capable of inverting the channel in the previous hop (regardless of the fading state of that hop) without limiting the output power. Furthermore, in [6], the end-to-end performance of dual-hop systems equipped with non-regenerative fixed gain relays is investigated and a specific relay is proposed, called semi-blind, that benefits from the knowledge of the first hop's average fading power. Recently, Tsiftsis et al presented a new upper bound for the end-to-end SNR and efficiently evaluated the average error probability in dual-hop collaborative diversity systems, especially at low SNRs [7].…”

Section: Introductionmentioning

confidence: 99%

“…These results are compared with a system which uses only the gain relay given by (6). from gl to gz, depends on the selected performance criterion and it can be determined after equating the formulae related to this criterion of the gains gl and g2 and solving numerically with respect to E. When the criterion considered is the outage probability, then Cth can be determined by equating (21) to [9, eq. -System wlh combined gain d a y -x --System ui!h g u relay g, Figure 3.…”

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confidence: 99%

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Wireless Transmissions with Combined Gain Relays over Fading Channels

Tsiftsis

Karagiannidis

Kotsopoulos

2006

Challenges in Ad Hoc Networking

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We present a dual-hop relayed wireless communication system where the gain of the relay, called combined gain relay (CGR), is produced after combining the channel state information from both hops, depending on the mean hop's signal-to-noise ratio (SNR). The proposed scheme can be efficiently applied in dual-hop transmissions with unbalanced mean SNRs due to the long-term fading effects produced by the movement of the user in the area served by the wireless network. The overall system performance is studied in Rayleigh fading channels. Closed-form expressions are derived for important system performance metrics, such as average end-to-end SNR, average error probability and outage probability. Furthermore, we investigate the CGR's average power consumption which in certain cases is lower compared to existed relays. Numerical results and simulations show an improvement in the end-to-end system performance.

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2010

Cooperative Communications

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A Performance Study of Dual-Hop Transmissions With Fixed Gain Relays

Cited by 751 publications

References 5 publications

Channel prediction in non-regenerative multi-antenna relay selection systems

Channel prediction in non-regenerative multi-antenna relay selection systems

Wireless Transmissions with Combined Gain Relays over Fading Channels

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