An iterative detection method for joint channel estimation in fbmc system

Abstract

The invention belongs to the technical field of modulated carrier systems, and discloses an iterative detection method for joint channel estimation in an FBMC system, which uses auxiliary pilots to eliminate interference in the first-order neighborhood, and completes the initial channel estimation value; joint iterative detection estimates outside the first-order neighborhood interference, and feed it back to correct the initial channel estimate, improve the estimation accuracy, and obtain accurate detection results. Compared with the traditional orthogonal frequency division multiplexing technology, the filter bank multi-carrier technology of the present invention does not need a cyclic prefix, and has higher frequency spectrum utilization rate, lower out-of-band interference and better synchronization robustness. Since the FBMC / OQAM system is orthogonal in the real number domain, but there is inherent imaginary part interference in the complex number domain, it brings great challenges to channel estimation. Simulation analysis results show that the algorithm proposed by the invention has fast convergence speed and high estimation precision.

Description

technical field [0001] The invention belongs to the technical field of modulated carrier systems, and in particular relates to an iterative detection method for joint channel estimation in an FBMC system. Background technique [0002] At present, the commonly used existing technologies in the industry are as follows: the filter bank multi-carrier (FBMC) transmission scheme was first proposed in the 1960s, and is an efficient multi-carrier modulation technique (MCM) suitable for multipath fading channels. Compared with the traditional CP-OFDM scheme, FBMC uses a shaped filter with good time-frequency focus (such as PHYDYAS filter), which has higher spectral efficiency, lower out-of-band interference and better synchronization robustness. The FBMC / OQAM system adopts offset quadrature amplitude modulation (OQAM) technology, which can only meet the requirements of quadrature in the real number domain, and there is inherent imaginary part interference in the complex number domain...

AI Technical Summary

Problems solved by technology

[0004] (1) has a large additional power overhead

[0005] (2) Leave blank the neighborhood that produces inherent interference to the pilot, but it will greatly reduce the spectrum utilization of the system

[0006] (3) A large number of matrix operations are involved at the sending end, and the complexity is very high

[0007] (4) Combine iteration and signal detection for channel estimation, but the convergence speed is slow and the estimation accuracy is limited

[0009] Compared with the traditional CP-OFDM system, the FBMC / OQAM system has higher spectral efficiency, lower out-of-band interference and higher synchronization robustness. However, the FBMC / OQAM system uses offset quadrature amplitude modulation (OQAM) technology, it can only meet the requirements of orthogonality in the real number field, and there is inherent imaginary part interference in the complex number field

This interference makes the channel estimation technology in the FBMC / OQAM system face great challenges. The low accuracy of the channel estimation method will offset the advantages of the FBMC / OQAM system

For inherent interference, existing channel estimation methods have problems such as large power overhead and slow iterative convergence.

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