Cross-layer resource allocation in orthogonal frequency multiple access systems based on channel distribution information

• Published in: IET communications Vol. 7; no. 5; pp. 439 - 447
• Main Author: Navaie, Keivan
• Format: Journal Article
• Language: English
• Published: Stevenage The Institution of Engineering and Technology 01.03.2013; John Wiley & Sons, Inc
• Subjects: CDI; channel distribution information; channel side information feedback; Channels; computational complexity; cross‐layer resource allocation; CSI feedback; Delay; discrete rate adaptation; dual decomposition method; elastic traffic; elastic users; fading channels; flexible rate requirements; frequency division multiple access; maximum average transmission power constraint; minimum guaranteed average delay; modulation levels; Multiple access; OFDM modulation; OFDMA systems; optimisation; optimisation problem; Optimization; orthogonal frequency multiple access systems; packet arrival rate; packet length distribution; parametric distribution; Resource allocation; streaming traffic; Subcarriers; suboptimal fading regions; suboptimal subcarrier allocation; telecommunication traffic; total average transmission rate; Traffic engineering; Traffic flow; wireless channel distributions; CDI; orthogonal frequency multiple access systems; suboptimal subcarrier allocation; channel side information feedback; elastic users; optimisation problem; modulation levels; optimisation; suboptimal fading regions; wireless channel distributions; fading channels; resource allocation; channel distribution information; CSI feedback; parametric distribution; OFDM modulation; flexible rate requirements; discrete rate adaptation; packet arrival rate; dual decomposition method; cross-layer resource allocation; elastic traffic; frequency division multiple access; packet length distribution; streaming traffic; OFDMA systems; total average transmission rate; telecommunication traffic; minimum guaranteed average delay; maximum average transmission power constraint; computational complexity
• ISSN: 1751-8628; 1751-8636
• DOI: 10.1049/iet-com.2012.0421

In this study, the authors propose a cross-layer resource allocation scheme for orthogonal frequency multiple access (OFDM) systems based on the subcarrier channel distribution information (CDI). Here, in contrast to most of the previous works, the authors consider practical discrete rate adaptation in which rate is adapted using a predefined set of modulation levels corresponding to fading regions. The OFDM system supports ‘streaming traffic’ that requires a minimum guaranteed average delay, as well as ‘elastic traffic’ with flexible rate requirements. The main objective is to maximise the total average transmission rate of elastic users, whereas the average delay is also guaranteed for streaming traffic, all subject to the maximum average transmission power constraint. The authors then propose an algorithm which finds suboptimal fading regions, as well as suboptimal subcarrier allocation based on dual decomposition method. In the proposed method, the solution of optimisation problem remains valid, until the channel distributions and/or the packet arrival and packet length distribution of the users are changed. This significantly reduces the computational complexity since there is no need to solve the optimisation problem for each channel side information (CSI) feedback. The proposed scheme also reduces the signalling overhead since corresponding to each user the CSI is required only for the assigned subcarriers. Particularly, the proposed method is suitable for cases in which wireless channel distributions is not changed, or can be simply estimated, for example, cases where a parametric distribution is fixed and only statistics such as average and variance is changed. Using simulations, the authors study the impact of number of fading regions and packet arrival rate on the achievable rate of elastic traffic.