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Performance evaluation and protocol design of fixed-rate and rateless coded relaying networks
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- Author / Creator
- Nikjah, Reza
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The importance of cooperative relaying communication in substituting for, or complementing,
multiantenna systems is described, and a brief literature review is presented.
Amplify-and-forward (AF) and decode-and-forward (DF) relaying are investigated and
compared for a dual-hop relay channel. The optimal strategy, source and relay optimal
power allocation, and maximum cooperative gain are determined for the relay channel. It
is shown that while DF relaying is preferable to AF relaying for strong source-relay links,
AF relaying leads to more gain for strong source-destination or relay-destination links.
Superimposed and selection AF relaying are investigated for multirelay, dual-hop relaying.
Selection AF relaying is shown to be globally strictly outage suboptimal. A necessary
condition for the selection AF outage optimality, and an upper bound on the probability of
this optimality are obtained. A near-optimal power allocation scheme is derived for superimposed
AF relaying.
The maximum instantaneous rates, outage probabilities, and average capacities of multirelay,
dual-hop relaying schemes are obtained for superimposed, selection, and orthogonal
DF relaying, each with parallel channel cooperation (PCC) or repetition-based cooperation
(RC). It is observed that the PCC over RC gain can be as much as 4 dB for the outage
probabilities and 8.5 dB for the average capacities. Increasing the number of relays deteriorates
the capacity performance of orthogonal relaying, but improves the performances of
the other schemes.
The application of rateless codes to DF relaying networks is studied by investigating
three single-relay protocols, one of which is new, and three novel, low complexity multirelay
protocols for dual-hop networks. The maximum rate and minimum energy per bit and
per symbol are derived for the single-relay protocols under a peak power and an average
power constraint. The long-term average rate and energy per bit, and relay-to-source usage
ratio (RSUR), a new performance measure, are evaluated for the single-relay and multirelay
protocols. The new single-relay protocol is the most energy efficient single-relay scheme
in most cases. All the multirelay protocols exhibit near-optimal rate performances, but are
vastly different in the RSUR.
Several future research directions for fixed-rate and rateless coded cooperative systems,
and frameworks for comparing these systems, are suggested. -
- Subjects / Keywords
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- Fixed-rate codes
- Rateless coding
- Cooperative communications
- Symbol error rate
- Amplify-and-forward relaying
- Maximal ratio combining
- Dual-hop relaying
- Energy efficiency
- Orthogonal relaying
- Large SNR approximation
- Protocol design
- Numerical optimization
- Acknowledgment signals
- Peak power constraint
- Degree of freedom
- Multiple access channels
- Fixed-rate coding
- Average power constraint
- Power allocation schemes
- Nonconcave fractional programming
- Energy per bit
- Power fairness
- Distributed space-time coding
- Relay-to-source usage ratio
- Outage probability
- Rayleigh fading
- Repetition coding
- Maximum-likelihood
- Optimal power allocation
- Rateless coded relaying
- Average capacity
- Decode-and-forward relaying
- Superimposed relaying
- Direct transmission
- Feedback communication
- Rateless codes
- Mutual information
- Fixed-rate coded relaying
- Parallel channel coding
- Bit error rate
- Relaying networks
- Outage optimality
- Single-hop communication
- Rate efficiency
- Energy per symbol
- Maximum achievable rates
- Cooperative gain
- Selection relaying
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- Graduation date
- Spring 2011
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- Type of Item
- Thesis
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- Degree
- Doctor of Philosophy
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- License
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.