KR19990000337A - Data communication device of code division multiple access method base station using local frequency - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base station data communication apparatus having a code division multiple access method capable of transmitting a control signal for communication data and additional services through one data transmission channel using a local frequency converted to a high frequency. A digital / analog converter for converting the voice data into an analog signal, a QPSK modulator for modulating the analog output of the digital / analog converter into a four-phase phase shift key signal, and a modulation signal in which the local frequency is leveled up and the control data is superimposed To generate a local signal for the mixer by fixedly fixing a phase of a reference frequency with a fixed first BPSK modulator, a first mixer for mixing outputs of a QPSK modulator and a BPSK modulator, a first filter for removing mixed noise of the first mixer PLL means for supplying a local signal of a constant phase output from the PLL means to a predetermined level. A voltage controlled oscillator for up, a second mixer for mixing the first mixed signal passed through the first filter and a reference frequency passed through the voltage controlled oscillator, a second filter for removing mixed noise of the second mixer, and the second filter And a high frequency amplifier for amplifying the second mixed signal passed through the filter to the transmission output level, and communicating with the subsystems of the base station through one wireless communication path. It can be used without affecting the radio frequency band effectively.

Description

Data communication device of code division multiple access method base station using local frequency

The present invention relates to a data communication apparatus of a code division multiple access type base station. In particular, the present invention relates to a data communication apparatus of a base station in which a code division multiple access method is used. A base station data communication apparatus using a code division multiple access method.

Conventionally, the frequency conversion of the base station is converted into a use frequency by using a voltage controlled oscillator (VCO) and a phase loop lock (PLL) means to achieve wireless communication. The intermediate frequency is converted into a QPSK (quadrature phase shift key) signal and converted into a mobile communication frequency band UHF (ultra high frequency). Frequency conversion is composed as shown below to drive each PLL chip based on reference frequency.

A block structure of a conventional code division multiple access type base station data communication apparatus will be described with reference to FIG.

A digital / analog converter 11 for converting input audio data into an analog signal, a QPSK modulator 12 for modulating the analog output of the digital / analog converter 11 into a four-phase phase shift key signal, and a reference frequency A plurality of PLL means (15, 17, 20) for generating a local signal for the mixer by fixing the phase of the constant and the local signal of a predetermined phase output from the PLL means (15, 17, 20) to a constant level The voltage-controlled oscillators 16, 17, 19 corresponding to the PLL means 15, 17, 20, and the output fv of the QPSK modulator and the output fc of the voltage-regulated oscillator 15, respectively, for level-up. ), A first mixer 13 for mixing), a first filter 14 for removing the mixed noise of the first mixer 13, and a first mixed signal fv + fc passing through the first filter 14. The second mixer 21 for mixing the reference frequency passed through the voltage controlled oscillator 17 and the second filter 22 for removing the mixed noise of the second mixer 21. And a high frequency amplifier 22 for amplifying the second mixed signal passed through the second filter 22 to a transmission output level.

Referring to the numerical calculation of the input signals fv and fc, fv = cos (At ± a), fc = sin (Bt), and the mixed signal fv + fc is fv + fc = 1/2 sin ((AB) t ± a) + 1/2 sin ((A + B) t ± a). The signal filtered through the second filter 22 becomes sin ((A + B) t ± a) and is transmitted to the receiver through an antenna. The receiver can mix sin (Bt) to detect the original signal fv.

The conventional code division multiple access method base station data communication apparatus is configured as described above, and in case of data communication with a sub-system of the base station, for example, a repeater, it is necessary to allocate a call channel to use a subscriber's use area. Modules such as terminals are added to enable data communication with the base station.

In such a conventional device, there is no separate device capable of additional communication with a subsystem of a base station, and a communication method using a modem is used for communication with a subsystem.

In the case of analog communication, the use of the base station subsystem is not frequent, but in the digital communication system, as the data communication and additional service functions are further increased, the base station subsystem is activated. It must be sought.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and uses a local frequency converted to a high frequency so that a code division can transmit a sub-system control signal for communication data and additional services through one data transmission channel. It is an object of the present invention to provide a multi-access base station data communication apparatus.

A base station data communication apparatus of a code division multiple access method of the present invention for achieving the above object comprises a four-phase phase shift of an analog output of a digital / analog converter for converting input voice data into an analog signal. QPSK modulator for modulating key signal, BPSK modulator for leveling up local frequency and generating control signal superimposed control data, First mixer for mixing output of QPSK modulator and BPSK modulator, Mixing of first mixer A first filter for removing noise, a PLL means for generating a local signal for a mixer by fixedly fixing a phase of a reference frequency, and a voltage adjustment for leveling up a local signal of a predetermined phase output from the PLL means to a predetermined level An oscillator, a second mixer for mixing a first mixed signal passed through the first filter and a reference frequency passed through the voltage controlled oscillator, And a second filter for removing the mixed noise of the second mixer, and a high frequency amplifier for amplifying the second mixed signal passed through the second filter to a transmission output level.

1 is a block diagram of a conventional code division multiple access method base station data communication apparatus;

2 is a block diagram of a data communication apparatus of a code division multiple access method base station using a local frequency according to the present invention.

*** Explanation of symbols for main parts of drawing ***

11,31: Digital / Analog Converter 12,32: QPSK Modulator

13,33: first mixer 14,34: first filter

15,17,19,37: Voltage controlled oscillator 16,18,20,38: PLL

21,41: second mixer 22,42: second filter

23,43: high frequency amplifier 30: BPSK modulator

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a data communication apparatus of a code division multiple access method base station using a local frequency according to the present invention. Referring to this figure, a block configuration of a data communication apparatus of a code division multiple access method base station using a local frequency is as follows.

First, a digital / analog converter 31 for converting input voice data into an analog signal, a QPSK modulator 32 for modulating the analog output of the digital / analog converter 31 into a four-phase phase shift key signal, and a local frequency. Level-up and BPSK modulator 30 for generating a modulated signal superimposed control data, a first mixer 33 for mixing outputs of the QPSK modulator 32 and the BPSK modulator 30, and the first mixer. A first filter (34) for removing the mixed noise of (33), a PLL means (38) for generating a local signal for a mixer by fixedly fixing a phase of a reference frequency, and a constant phase output from the PLL means (38) The voltage controlled oscillator 37 for leveling up the local signal to a predetermined level, the first mixed signal fv + fc passed through the first filter 34 and the reference frequency passed through the voltage controlled oscillator 37 The second mixer 41 to mix, the mixed job of the said 2nd mixer 41 The is achieved by having a second filter 42, a high-frequency amplifier 43 for amplifying the second mixed signal passed through the second filter 42 to the transmission power levels to eliminate.

Unlike the configuration of the conventional base station data communication apparatus, the configuration of the present invention can maximize the wireless communication channel by using a signal modulated with control data as a local frequency while transmitting together with the communication channel with the subsystem. As shown in FIG. 2, fv signal in which voice data is modulated by a QPSK signal and fd in which control data for controlling a subsystem are modulated by BPSK are used as local frequencies.

When the QPSK modulated signal fv and the BPSK modulated signal fd of the control data are amplified, converted, and transmitted, fv + fd is transmitted, the receiving subsystem demodulates only the control data by filtering only the modulated signal of the control data.

The present invention is a structure that modulates and mixes local frequency fc with control data, which can be proved by the following equation.

The QPSK modulated signal fv = cos (At ± a) and the BPSK modulated signal fd = sin (Bt ± b) of the control data. The mixed signal fv + fd of the QPSK modulated signal fv and the control data BPSK modulated signal fd becomes cos (At ± a) sin (Bt ± b).

At this time, cos (At ± a) sin (Bt ± b) = 1 / 2sin ((AB) t + (a ± b)) + 1 / 2sin ((A + B) t + (a ± b) and the filtered signal Is sin ((A + B) t + (a ± b), where (a + b) is the phase deviation but the phase difference in cos (At ± a), which is the QPSK modulated signal fv, It will not affect.

At the time of reception, cos (Bt + b) can be extracted by mixing sin (At + a) with the input signal. Passing this signal through the demodulator allows the control data to be recovered, and the control data can be used to communicate with the subsystem.

According to the present invention as described above, it is possible to communicate with the subsystems of the base station through one wireless call path, and to use the wireless data band effectively without affecting other call subscribers. There is a number.

Claims (1)

Digital / analog converter for converting input voice data into analog signal, QPSK modulator for modulating analog output of digital / analog converter into four-phase phase shift key signal, Modulation of leveling up local frequency and superimposing control data A BPSK modulator for generating a signal, a first mixer for mixing outputs of a QPSK modulator and a BPSK modulator, a first filter for removing mixed noise of the first mixer, and a fixed local phase for the mixer by fixing a phase of a reference frequency A PLL means for generating, a voltage controlled oscillator for leveling up a local signal of a predetermined phase output from the PLL means to a predetermined level, a first mixed signal passed through the first filter and a reference frequency passed through the voltage controlled oscillator The second mixer to be mixed, the second filter to remove the mixed noise of the second mixer, and the second mixed signal passed through the second filter A data communication apparatus using a local frequency, characterized in that having been made in the high-frequency amplifier for amplifying a.