Second Order Suboptimal Power Allocation for MIMO-OFDM Based Cognitive Radio Systems

• Tien Hoa Nguyen,
• Thanh Hieu Nguyen,
• Van Duc Nguyen,
• Duyen Trung Ha,
• Guilllaume Gelle,
• Hyunseung Choo,

Vol. 8, No. 8, August 28, 2014
10.3837/tiis.2014.08.004, Download Paper (Free):

• cognitive radio
• MIMO
• OFDM
• Power Allocation Optimization

Abstract

This paper proposes an ef
cient and low complexity power-loading algorithm for MIMO-OFDM downlink based cognitive radio system that maximizes the sum rate of single secondary user (SU) under constraints on the tolerable interference thresholds between secondary user and primary users frequency bands and the total transmission power. Our suboptimal algorithm is based on the 2nd order interference tracking and nulling mechanism to allocate transmission power of the subcarriers among SUs scheme. The performance of our proposed suboptimal scheme is compared with the performance of the classical power loading algorithms, e.g., water filling, 1st order interference tracking, nulling, and other suboptimal schemes. Numerical results show that our algorithm has low complexity but obtains a higher channel capacity than that of some previous suboptimal algorithms in some scenarios. We dedicate also that for a given interference threshold, the 2nd order interference tracking mechanism has dynamic number of nulling position instead fixed number of nulling position.

Statistics

Cite this article