Diversity receiving method and device of PDT (Police Digital Trunking) digital and analog dual-system trunking system

Abstract

The embodiment of the invention discloses a diversity receiving method and a diversity receiving device of a PDT (Police Digital Trunking) digital and analog dual-system trunking system. By adopting an intermediate-frequency digital receiving technique, combing a space diversity method and completing the signal processing of diversity combination in baseband signals, the uplink signals of the system can be effectively improved and the diversity receiving function of the PDT digital and analog compatible system is simply and efficiently realized at a low cost. The method provided by the invention comprises the steps of respectively receiving signals through three loops of receiving antennas; respectively conducting preprocessing to the signals and transmitting the preprocessed signals to a baseband treatment module; respectively filtering the preprocessed signals to obtain filtering signals; respectively calculating the channel parameter of a channel corresponding to each filtering signal to obtain processing data; combining the processing data and conducting filtering processing to the combined data according to digital and analog requirements; and transmitting the combined data obtained after filtering processing to a digital and analog mode selection module.

Description

technical field [0001] The embodiments of the present invention relate to the communication field, and in particular to a diversity receiving method and device for a PDT digital-analog dual-system trunking system. Background technique [0002] The existing wireless trunking system mainly adopts a large-area coverage method. The base station is set on the top of a mountain or a high-rise building, and uses a high-power, high-gain omnidirectional antenna to transmit. The downlink signal, that is, the signal from the base station to the mobile station is strong. However, mobile stations, especially handheld stations, are difficult to use high-power, high-gain antennas to enhance the transmission signal due to factors such as size, weight, power consumption, and design process. Therefore, the uplink signal of the handheld station, that is, the signal from the mobile station to the base station Weak, the base station cannot receive the uplink signal of the mobile station well or ...

AI Technical Summary

Problems solved by technology

[0010] However, using the solution of adding base stations will bring additional frequency resource occupation. In the private network cluster system where the frequency resources themselves are very tight, this method of improving the uplink signal at the cost of increasing the frequency resource burden of the system is not very good. suitable

At the same time, the addition of base stations will bring many cross-base station operations such as location registration, handover, roaming, etc., which will increase the data load of link communication, increase the complexity of system operation, and reduce the reliability of system work.

When setting up the same-frequency transponder, it is necessary to consider the signal isolation between the sending and receiving. Since the transmitting and receiving of the same-frequency transponder work at the same frequency point, when the isolation between sending and receiving is not handled well, the receiving of the same-frequency transponder will withdraw its own transmission. The signal forms a signal loop between receiving and transmitting, and there is a problem of self-excitation

Using this method to improve the uplink signal of the system is relatively difficult to implement

Moreover, regardless of adding base stations or setting up same-frequency transponders, it will increase the workload and cost of construction, management and maintenance.

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