J4 ›› 2012, Vol. 39 ›› Issue (6): 176-180+194.doi: 10.3969/j.issn.1001-2400.2012.06.029

• Original Articles • Previous Articles     Next Articles

Spectrum sensing method for the time-frequency gathering density analysis

ZHENG Wenxiu   

  1. (School of Communication and Info. Eng., Xi'an Univ. of Post & Telecommunications,  Xi'an  710121, China)
  • Received:2011-12-02 Online:2012-12-20 Published:2013-01-17
  • Contact: ZHENG Wenxiu E-mail:zhengwenxiu@xupt.edu.cn

Abstract:

Aiming at the primary users' signals with single carrier or MSK modulation, a novel spectrum sensing algorithm is proposed based on the time-frequency gathering density analysis. The time-frequency ridge line of the received data's mutual correlation is calculated, with whose statistics the probability vector is formed. The time-frequency gathering density is defined to evaluate the gathering level of the time-frequency dots according to the fact that the signal energy gathers around the carrier frequency and that the noise energy disperses evenly among all frequencies. The gathering threshold is set to judge the existence of the primary user's signal. Simulation indicates that the proposed algorithm is effective for both the normal and fading channel and maintains good detecting performance at lower SNRs and that with the same noise power uncertainty, the false alarm of the proposed algorithm is lower than that of the energy detection method.