Iterative detection method of joint channel estimation in FBMC system

Abstract

The invention belongs to the technical field of the modulation carrier system, and discloses an iterative detection method of joint channel estimation in a FBMC system. The method comprises the following steps: eliminating interference in a first-order neighbor domain by using auxiliary pilot to accomplish a channel initial estimation value; estimating the interference out of the first-order neighbor domain by uniting the iterative detection, and feeding back the interference to modify the channel initial estimation value, thereby improving the estimation precision and acquiring an accurate detection result. Compared with the traditional orthogonal frequency division multiplexing technology, and the multi-carrier technology of a filter bank has higher spectrum use ratio, lower out-of-bandinterference and better synchronization robustness without using the cyclic prefix. Since the FBMC/OQAM system satisfies the orthogonality at the real-number field, and inherent imaginary part interference is existent in the complex field, and the great challenge is brought to the channel estimation. The simulated analysis result shows that the algorithm provided by the invention is fast in convergence rate and high in 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 existing technologies commonly used in the industry are as follows: The filter bank multi-carrier (FBMC) transmission scheme was first proposed in the 1960s, and it 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 do...

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.

Images