Pilot frequency design method based on sparse channel estimation in cognitive radio

Abstract

The invention discloses a pilot frequency design method based on sparse channel estimation in a cognitive radio. The method comprises the following steps of: randomly selecting sub carriers from a set C consisting of available sub carriers acquired by spectrum sensing to form a group of initial pilot frequency configurations P; generating a candidate set according to C and P, selecting an optimal element at each element position in the P from the candidate set, selecting the best element from the optimal elements, finding the element position corresponding to the best element, replacing the best element for the original element at the position, and keeping the elements at other positions in the P unchanged to form a new group of pilot frequency configurations P1; generating a new candidate set according to C and P1, repeating the operation until the new generated pilot frequency configurations are constant, wherein the constant pilot frequency configurations are preferable pilot frequencies; and repeating the steps for many times, and selecting the best one from the preferable pilot frequencies as an optimized pilot frequency configuration. The method has the advantages of high convergence speed, parallel computation feasibility, low mean square error, low error rate and the like.

Description

technical field [0001] The present invention relates to the communication field, to a cognitive radio system, and in particular to a pilot design method based on sparse channel estimation in the cognitive radio. Background technique [0002] The rapid development of mobile communication systems and various communication services has put forward higher demands on spectrum resources, and the shortage of spectrum resources has become increasingly significant. On the other hand, the authorized frequency bands are not fully utilized, and a large number of frequency bands are idle or rarely utilized. Thus, a cognitive radio (Cognitive Radio, CR) technology is produced. Using this technology, other users can also use these frequency bands under the premise of ensuring that authorized users use their frequency bands first; therefore, this technology is expected to greatly improve the spectrum utilization of existing frequency bands without opening up new frequency bands. [0003] ...

AI Technical Summary

Problems solved by technology

However, the second scheme uses the "random search" algorithm to obtain the pilot arrangement, which is inefficient and cannot guarantee system performance in practical applications

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