Cognitive radio (CR) is proposed to automatically detect and exploit unused spectrum while
avoiding harmful interference to the incumbent system. In this paper, we emphasize the …

The future wireless communication is expected to be able to improve the efficiency of
spectrum usage. To solve the challenge of spectrum shortage, an innovative opportunistic …

In cognitive radio (CR), a cognitive user must cease transmission or reduce the transmit
power at the band where a primary system (PS) is detected. To this end, a popular method …

Future generation wireless communication systems will face the problem of providing
efficient spectrum allocation to meet the growing demands of various services. In real-time …

This paper considers a new power strategy and channel-allocation optimization for
secondary users (SUs) in an orthogonal frequency-division multiplexing (OFDM)-based …

The future wireless communication is expected to be able to improve the efficiency of
spectrum usage. To solve the challenge of spectrum shortage, an innovative opportunistic …

Recent works in cognitive radio (CR) have suggested multicarrier communication based on
orthogonal frequency-division multiplexing (OFDM) for CR networks. In this paper, we …

Quick development of wireless communication makes the spectrum scarcity as a one of the
serious problems. Cognitive radio (CR) is considered to be one of the possible solutions to …

This paper presents a two-step downlink resource allocation algorithm for multicarrier based
cognitive radio systems. The algorithm allocates the subcarriers to the users in the first step …

Cognitive radio is a promising approach for efficient utilization of radio spectrum. Due to its
high spectral efficiency and flexibility, OFDM is considered as a good signaling scheme for …