A Feedback Superposition Energy Detection Method to Solve the Random Arrival of Users

Abstract

The invention discloses a feedback stack energy detection method solving user random arrival. The method comprises the steps of setting a target false-alarm probability Pf<DES>, the detection time Tsens of a feedback stack energy detection algorithm and a sampling frequency spectrum fs of the feedback stack energy detection algorithm; working out a judgment threshold eta'; calculating a statistical decision amount Y of the feedback stack energy detection algorithm; if Y>=eta', determining that users (primary users or secondary users) exists in a channel H1; if Y<eta', determining that no users (primary users or secondary users) exist in a channel H0. According to the feedback stack energy detection method solving user random arrival, due to the fact that instant energy values of sampling points of the second half portion of an energy detection algorithm detection period are added to instant energy of sampling points of the first half portion of the energy detection algorithm detection period, on the premise that the detection time is not prolonged, the energy proportion of use signals in the statistical decision of the energy detection algorithm is improved; the detection performance for user cognition can be improved, the probability that user data collide with each other in a cognitive radio system is reduced, and therefore the SU data throughout is improved.

Description

technical field [0001] The invention relates to energy detection technology in cognitive radio technology, in particular to a feedback superposition energy detection method for solving random arrival of users. Background technique [0002] Cognitive Radio (CR), as a dynamic spectrum reuse technology, can improve spectrum utilization and effectively utilize scarce spectrum resources. In CR technology, energy detection (Energy Detection, ED) has been widely used due to its simplicity and low complexity. Most of the current research on idle spectrum detection is based on the assumption that the communication status of the authorized user / primary user (Primary User, PU) does not change during the detection phase, that is, it is assumed that the PU either exists or does not exist during the entire detection period. exist. However, in the actual CR environment, the activity state of the PU is likely to change during the detection period, especially in low signal-to-noise ratio (...

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Problems solved by technology

figure 2 Medium SU 0 at t 1 Perceive the PU frequency band at all times, at t 3 The detection is completed at all times and the PU is detected to be idle, then the SU 0 at t 3 Start to transmit your own data at all times, the light blue part in the figure indicates SU 0 data; but SU 0 Soon after starting detection, SU also arrives in the network, at t 2 Start to perceive the PU frequency band at any time, which causes in the detection cycle of SU, at [t 2 ,t 3 ] time period contains only AWGN signal, in [t 3 ,t 4 ] time period contains SU 0 Mixed signal of signal and AWGN signal

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