Radio Resource Allocation with The Fairness Metric for Low Density Signature OFDM in Underlay Cognitive Radio Networks.

Linda Meylani,M Sigit Arifianto,Adit Kurniawan

doi:10.3390/s19081921

Linda Meylani, M Sigit Arifianto + Show 1 more

Open Access

https://doi.org/10.3390/s19081921

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Abstract

Low density signature orthogonal frequency division multiplexing (LDS-OFDM), one type of non-orthogonal multiple access (NOMA), is a special case of multi-carrier code division multiple access (MC-CDMA). In LDS-OFDM, each user is allowed to spread its symbols in a small set of subcarriers, and there is only a small group of users that are permitted to share the same subcarrier. In this paper, we study the resource allocation for LDS-OFDM as the multiple access model in cognitive radio networks. In our scheme, SUs are allocated to certain subcarriers based on minimum interference or higher SINR in each subcarrier. To overcome the problem where SUs were allocated less than the subcarriers, we propose interference limit-based resource allocation with the fairness metric (ILRA-FM). Simulation results show that, compared to the ILRA algorithm, the ILRA-FM algorithm has a lower outage probability and higher fairness metric value and also a higher throughput fairness index.

Highlights

To improve the spectrum efficiency, cognitive radio (CR) systems allow the secondary user (SU) to access the primary user’s (PU) spectrum in three schemes of dynamic spectrum access (DSA) [1]; these are interweave, underlay, and overlay
We propose resource allocation for low density signature (LDS)-OFDM users in underlay CR systems based on the interference limit with the fairness metric to increase spectrum utilization
To evaluate the performance of the proposed algorithm, we considered the case with 10 PUs and 200 SUs

Summary

Introduction

To improve the spectrum efficiency, cognitive radio (CR) systems allow the secondary user (SU) to access the primary user’s (PU) spectrum in three schemes of dynamic spectrum access (DSA) [1]; these are interweave, underlay, and overlay. The SU is allowed to access the spectrum simultaneously with the PU, as long as it does not cause any degradation in PU performance. The SU is permitted to transmit simultaneously with the PU provided that the SU allocates part of its transmit power to relay the PU’s signal. The work in in [2,3,4,5] used multi-carrier code division multiple access (MC-CDMA) as their spectrum access model and designed interference cancellation (IC) techniques to combat the interference

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