EKF-based TC-OFDM receiver code tracking method and device

Abstract

The embodiment of the invention provides an EKF-based TC-OFDM receiver code tracking method and a device. The method comprises the following steps of receiving a target signal at the current moment, acquiring a local signal generated by a TC-OFDM receiver itself, subjecting the target signal and the local signal to correlation operations so as to obtain a signal observed value at the current moment, acquiring a state estimation value at the previous moment of the current moment, subjecting the signal observed value at the current moment and the state estimation value at the previous moment of the current moment to calculation based on the EKF algorithm, and obtaining a state estimation value at the current moment. The state estimation value comprises a code phase error and a signal amplitude. The code phase error and the signal amplitude are jointly used the state estimation value of the EKF for calculation. Therefore, the convergence speed and the robustness of a tracking loop are improved. As a result, the tracking sensitivity of the TC-OFDM receiver is improved.

Description

technical field [0001] The present invention relates to the field of communication technology, in particular to a code tracking method for time division code division orthogonal frequency division multiplexing (Time & Code Division-Orthogonal Frequency Division Multiplexing, TC-OFDM) based on Extended Kalman Filter (Extended Kalman Filter, EKF) and devices. Background technique [0002] In the TC-OFDM positioning system based on the terrestrial mobile broadcast network, the receiver is usually used for signal acquisition and tracking. Among them, the signal tracking mainly includes the code tracking process to track the captured signal, determine its code phase, and then achieve the purpose of positioning. [0003] figure 1 It is a schematic diagram of the existing code tracking loop structure. Such as figure 1 As shown, the existing code tracking loop is composed of a carrier stripping operator, a code generator, a set of leading correlators, a set of lagging correlator...

AI Technical Summary

Problems solved by technology

However, during code tracking, due to noise effects and other reasons, there may be sudden changes in the signal amplitude

In this case, the received base station signal may exceed the signal amplitude threshold that the code ring discriminator in the TC-OFDM receiver can handle. At the same time, because the code ring discriminator has nonlinear factors when discriminating the phase, it is prone to code ring loss. The phenomenon of lock, that is, the phenomenon that the code phase error cannot be calculated

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