Echo cancellation device of law enforcement recorder

Abstract

The invention discloses an echo elimination device of a law enforcement recorder. The echo elimination device comprises a far-end user, a far-end user voice input device, a far-end user voice output device, a first signal converter, a radio transmission device, a voice processing device, a second signal converter, a local user voice output device, a local user voice input device and a local user;the far-end user is connected through the far-end user voice input device, the first signal converter and the radio transmission device; the radio transmission device is connected with the local userthrough the voice processing device, the second signal converter and the far-end user voice output device; and the output end of the local user is connected with the input end of the second signal converter through the local user voice input device. The echo elimination device of the law enforcement recorder of the present invention is not interfered by the output data of the far-end user in the local user voice input device, ensures the effect of echo cancellation during a certain period, and improves the efficiency and effectiveness of echo cancellation on the whole.

Description

technical field [0001] The invention relates to the technical field of echo cancellation, in particular to an echo cancellation device of a law enforcement recorder. Background technique [0002] In the intercom of law enforcement recorder and platform system, it is necessary to carry out real-time voice communication between two or more parties. Usually, an external speaker is used to play the sound, which will inevitably produce an echo, that is, after one party speaks, the sound is played through the other party's speaker. Then it is picked up by the microphone of the other party and transmitted back to itself. If the echo is not processed, it will affect the quality of the call, will form sound oscillations, and generate howling. It requires technology to implement echo cancellation. Existing echo cancellation devices mainly use echo estimation The value processor compares the electric signal sent by the local user with the original electric signal sent by the remote use...

AI Technical Summary

Problems solved by technology

[0002] In the intercom of law enforcement recorder and platform system, it is necessary to carry out real-time voice communication between two or more parties. Usually, an external speaker is used to play the sound, which will inevitably produce an echo, that is, after one party speaks, the sound is played through the other party's speaker. Then it is picked up by the microphone of the other party and transmitted back to itself. If the echo is not processed, it will affect the quality of the call, will form sound oscillations, and generate howling. It requires technology to implement echo cancellation. Existing echo cancellation devices mainly use echo estimation The value processor compares the electric signal sent by the local user with the original electric signal sent by the remote user. When the comparison result is within the set threshold range, the repeated electric signal in the electric signal sent by the local user is deleted. However, this method has the following disadvantages: the echo estimation processor is based on the estimation of the statistical characteristics of the input and output signals, and adopts a specific algorithm to automatically adjust the processor coefficients to achieve an algorithm or device with the best filtering characteristics. , the echo estimation value processor updates and adjusts the weighting coefficients for each sample of the input signal sequence according to a specific algorithm, so that the mean square error between the output signal sequence and the expected output signal sequence is the smallest, that is, the output signal sequence is close to Expected signal sequence. In this process, the echo estimation value processor needs to keep the coefficients stable after convergence, so as to ensure that it is not disturbed by the output data of the remote user in the local user's voice input device. On the other hand, the echo estimation value processor needs to be at any time Keep updated to ensure that the changing echo path can be tracked. The contradiction between the rapid convergence and high stability of the echo estimation processor restricts the development of echo cancellation technology

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