A New Fair Resource Allocation Algorithm in multiuser OFDM Cognitive Radio Systems

• 1、School of Information and Communication Engineering, BUPT

Abstract：In the situation of scarcity and low utilization of spectrum resource, Cognitive Radio (CR) provides a good concept for improving the utilization of spectrum. OFDM technique is a preferred technique for CR systems. In this paper, a new fair resource allocation named Talmud algorithm based on the consumer’s biddings for resource in multiuser OFDM Cognitive Radio systems was presented; we also researched the Subcarrier Nulling on the sides of the Primary User（or Authorized User）in order to mitigate the interference. The Talmud resource allocation algorithm was divided into two steps: (1) Computing the output belongings vector according to Talmud algorithm based on the users’ biddings; (2) Keep the transmission power and the interference introduced by Secondary Users (or Cognitive Radio Users) below the desired threshold, and maximize the transmission rates with the joint subcarrier assignment and bit loading dynamic allocation algorithm based on greedy algorithm. The simulation results show that our proposed algorithm outperformed the ordinary proportional allocation in the performance of Proportional Fairness and the total throughput. Another result is that the Subcarrier Nulling approach outweighs the greedy algorithm without nulling.

Keywords： OFDM Cognitive Radio Talmud fairness allocation greedy algorithm Subcarrier Nulling or relevant subcarrier zero-bit loading