In-band common frequency digital cordless telephone

Abstract

The present invention is an in-band co-frequency digital cordless telephone, which consists of two parts: a main machine and a slave machine, and its circuit part consists of a control circuit, a digital signal processing circuit, a radio frequency transceiver circuit, a voice transceiver circuit, a storage circuit, a display circuit, and a keyboard input circuit , analog-to-digital conversion circuit, interface circuit and power supply circuit are electrically connected to each other. The present invention adopts the same frequency band as the existing analog cordless telephone in my country, can save precious frequency spectrum resources, greatly reduces requirements on required components and production and testing equipment, and has low cost. The present invention integrates the latest digital signal processing technologies such as speech coding, channel coding, digital modulation and demodulation, and digital channel equalization, and adopts a single-chip integrated circuit chip to realize the advantages of good call quality, high spectrum utilization rate, strong anti-interference, It has the advantages of good confidentiality, easy product update and function expansion, and can be compatible with the third-generation mobile communication system.

Description

(1) Technical field [0001] The invention relates to the technical field of communication, signal processing and software radio, in particular to an in-band co-frequency digital cordless telephone. (2) Background technology [0002] At present, my country's cordless phones are still dominated by analog cordless phones. There are many deficiencies in analog telephones: first, analog cordless telephones transmit analog signals, the signal processing method is simple, the power consumption is relatively large, and the influence of interference and noise cannot be effectively eliminated, resulting in unsatisfactory call quality in many cases; Second, the frequency utilization rate of analog cordless phones is not high, and the channel capacity is low. The cordless phone standard formulated in my country in 1994 is 20 pairs of frequencies of 45 / 48MHz, and the frequency bandwidth occupied by each channel is 25kHz; The analog cordless phone uses analog modulation transmission, which ...

AI Technical Summary

Problems solved by technology

There are many deficiencies in analog telephones: first, analog cordless telephones transmit analog signals, the signal processing method is simple, the power consumption is relatively large, and the influence of interference and noise cannot be effectively eliminated, resulting in unsatisfactory call quality in many cases; Second, the frequency utilization rate of analog cordless phones is not high, and the channel capacity is low. The cordless phone standard formulated in my country in 1994 is 20 pairs of frequencies of 45 / 48MHz, and the frequency bandwidth occupied by each channel is 25kHz; The analog cordless phone uses analog modulation transmission, which is easy to be illegally tapped and eavesdropped, and the security cannot be fully guaranteed; fourth, the analog cordless phone mostly uses discrete components to form a circuit, the degree of integration is not high, the volume is large, and the function consumes more

Therefore, it is difficult to realize, the cost is high, and there is a tendency to be replaced by GSM

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