Method for estimating discontinuous orthogonal frequency division multiplying channel based on compressed sensing

Abstract

The invention discloses a method for estimating a discontinuous orthogonal frequency division multiplying channel based on compressed sensing. The method comprises the steps of: designing a channel estimating pilot pattern, selecting a pilot pattern and estimating a channel frequency domain response. The pilot pattern is selected by using two schemes. The first scheme is to maintain a traditional uniform pilot pattern and automatically disable a pilot at a disabled sub-carrier in order that an available pilot presents a natural non-homogeneity. The second scheme is to fix the quantity of the pilots and utilize the following optimized problems to search P sub-carrier transporting pilot marks in the available sub-carrier based on a criterion of recovering matrixes correlation minimization, wherein L is the channel length, P is the number of pilots, and N is the total number of OFDM system sub-carriers. The method of the invention can be applied to various scenes of the disabled sub-carrier. Through the method of the invention with fewer pilots, the acquired channel estimating property and system error ratio property are better than those acquired by using the other methods in prior art.

Description

Technical field The present invention proposes a channel estimation method based on compressed sensing theory in a cognitive radio non-continuous orthogonal frequency division multiplexing (NC-OFDM) system. It belongs to the technical field of pilot-aided channel estimation for communication systems. Background technique In recent years, with the continuous growth of high-speed wireless communication services, a new generation of mobile communication systems needs to use a wider frequency band to provide users with wireless communication services with a rate of hundreds of megabytes, and the shortage of spectrum resources has become increasingly significant. However, the scarcity of spectrum resources is a relative scarcity. Current research shows that the licensed spectrum frequency bands are not fully utilized, a large number of spectrum resources are in idle state, and the spectrum above 3GHz is hardly used. The reason for this phenomenon At present, the allocation of spect...

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Problems solved by technology

Recently, some scholars at home and abroad have studied the application of compressive sensing technology in ultra-wideband (UWB) system and OFDM system channel estimation, but there is no literature research on applying compressive sensing-based channel estimation to NC-OFDM system channel estimation.

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