JPS5847340A - Phase compensation controlling system of return signal - Google Patents

Abstract

PURPOSE:To stabilize the compensation of phase for a mobile communication system, by discriminating the signal frequency for monitor of receiving talking circuit of a talking circuit before setting the talking circuit and setting previously the corresponding degree of phase compensation. CONSTITUTION:For a mobile communication system which monitors a talking circuit and measures the distance between two stations, the SAT signal frequency discrimination code for monitor of talking circuit which is transmitted previously is reproduced at a data receiving part 26 through a control circuit and before the talking circuit is set. The discrimination code is then transferred to a central processing part 27 to be used for necessary processes and for control of the terminal device. The degree of phase compensation corresponding to the SAT frequency which is designated by the SAT frequency discrimination code is read out of a storage part 28 among the discrimination codes at the part 27. Based on this data of the part 28, the degree of phase shift is set for a variable phase shifter 24. In such a way, the accurate compensation of phase is made possible to the designated SAT frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phase compensation control system for return signals, and particularly to a method for controlling phase compensation of return signals, and in particular, for a mobile communication system consisting of a mobile station such as a mobile telephone terminal device and a base station, a plurality of different signals (for example, three waves) are transmitted. For telephone line monitoring using the frequency of
This invention relates to a phase compensation control method for a return signal of an AudioTame (SAT) signal.

A conventionally used phase compensation method as described above is shown in FIG. FIG. 1 is a block circuit diagram of a phase compensation circuit of a mobile station.
0, band pass filter (BPF) 11, phase locked loop (PLL) 12, SATA wave number detector (Freq
DET) 13, variable phase shifter (VPS) 14, output end 1
Consists of 5. In the circuit of Fig. 1, the input terminal l
The received OJ signal Rx is supplied to O, and the received SATA signal is extracted and transmitted to BPF II and PLL 12. Different frequencies (for example, 5'970Hz @ 6000Hz, 6030H
z) is used, and in order to compensate for the different stationary phase differences in BPFII and PLL 12 depending on the frequency of the received SAT signal, the signal from which the noise component has been removed in PLL 12 is supplied to FreQ DET 13,
The frequency of the received signal is detected from the counted value K.

A phase compensation amount corresponding to the frequency of the received signal detected by the Freq DET 13 is set in the VPS 14, thereby controlling the phase of the return SAT signal Tx outputted to the output terminal 15.

By the way, if the above-mentioned SAT frequency detector 13 and variable phase shifter 14 are not used, the return SAT signal corresponding to the received SAT signal (which has a different frequency depending on the communication line)
A problem arises in that the phase error of the signal becomes too large.

However, in the phase compensation control method shown in FIG. 1, when the received electric field strength significantly decreases due to fading etc. and the noise component in the received signal increases, jitter increases in the output of the PLL 12, which causes Freq DET 13 As a result, the correct frequency cannot be detected in
The problem is that the phase shift amount of 814 is incorrectly set.

tfI-1 In this phase compensation circuit, the received signal is
The frequency K counted in req-DET 13 is 1i! The correct frequency cannot be obtained unless the counting time is lengthened because of the edict.Therefore, when processing a burst-like received signal, there is a problem that correct phase compensation cannot be performed for the head portion of the burst.

The main object of the present invention is to solve the above-mentioned problems of the conventional system, and based on the idea of using the SAT frequency identification code transmitted through the control line before the call line is set up at the mobile station, the mobile station receives the call line. To provide a phase compensation control system for a return signal that can identify a SAT signal frequency before setting up a telephone line, set a corresponding phase compensation amount in advance, and perform stable phase compensation.

In the present invention, a base station and a mobile station are provided, and a control line and a communication line are provided between the two stations, and the communication line is set by a control signal transmitted on the control line, and During a call, a 1tivL viewing signal (SAT signal) is transmitted from the base station to the mobile station over the line, and the mobile station sends back a return SAT signal synchronized with the received SAT signal to the base station. , the transmitted S at the base station
In a mobile communication system that measures the phase difference between the AT signal and the returned SAT signal, and then monitors the communication line and measures the distance between the two stations, SA of different frequencies is used.
Control of a phase compensation circuit provided in the mobile station to compensate for a phase error occurring within the mobile station with respect to the T signal is transmitted in advance through the control line before setting up the communication line. A phase compensation control method for a return signal is provided, characterized in that the signal is controlled using a code.

A phase compensation control system for a return signal as an embodiment of the present invention will be explained below with reference to FIG.

The phase compensation circuit shown in FIG. 2 includes a 20° band-pass filter (BPF) 21. Phase quadruple loop (P
LL) 22, frequency detector (FreqDET) 23, variable phase shifter (VF6) 24, output end 25, data receiving section (DT RECV) 26, central processing section (CPU)
27, and a storage section (MEM) 28. Of these, DT RECV 26, CPU 27, M
EM 2B is provided to perform various transmission/reception code processing in the mobile station, and can have various functions other than the phase compensation control function according to the present invention.

In the circuit of FIG. 2, the signal Rx received at the mobile station, i.e., the car telephone terminal, is supplied to the input terminal 20 and received at the BPF 21 and PLL 22.
The AT signal is extracted and reproduced, and the received SAT signal is further subjected to phase compensation in the VF 624, and is outputted from the output terminal 25 as a return SAT signal Tx. Received signal RxFi
, also supplied to DTRICV 26-tt, DT R
The code signal in the received signal is regenerated in the ECV 26 and transferred to the CPU 27.

In a car telephone terminal device, when a call line is set up, a series of code signals (call line instruction signal) including an 8AT frequency identification code is received prior to the KSATSAT signal. These codes are reproduced in the DTRECV 26 and then transferred to the CPU 27, where they are used for necessary processing numbers and control of the terminal device. Among these codes, S A specified by the SAT frequency identification code
The amount of phase compensation corresponding to the T IN wave number is read out by the CPU 27 from data stored in advance in the MEλ 128 .

CPU 27 Fi, VPS based on this data
A phase shift amount of 24 is established, thereby providing accurate phase compensation for the specified SAT frequency.

In addition, these series of code signals include lTh correction detection codes, and the BER (
Since the existence of vA9 becomes clear even when Bit Error Rate ) deteriorates, the probability of setting an incorrect amount of phase compensation can be extremely reduced.

Further, although the circuit 1cFreq DET 23 in FIG. 2 is not directly related to the control of the top phase compensation amount as in the case of FIG. It can be used to notify the CPU 27 of the wave number.

According to the present invention, it is possible to provide a phase compensation control method for a return signal that can preset the amount of mm compensation corresponding to the SAT signal frequency and can perform stable phase compensation.

[Brief explanation of the drawing]

fI'SIF is a circuit diagram showing a conventional phase compensation control method, and FIG. 2 is a circuit diagram showing a phase compensation control method as an embodiment of the present invention. (Explanation of symbols) 10.20: Input end, 1i, 21: Band pass filter, 12.22: Phase locked loop, 13t23: Frequency detector, 14.242 Variable phase shifter, f5*25: Output end, 26 : data receiving section, 27: central processing section, 28: storage section.

Claims (1)

[Claims] A control line and a communication line are provided between the two stations, and the communication line is set by a control signal transmitted through the control line, and the communication line is set by a control signal transmitted through the control line, and the communication line is set by a control signal transmitted through the control line. A line monitoring signal (SATA number) is transmitted from the base station to the mobile station, and the mobile station sends back a return SATA signal synchronized with the received SA signal to the base station. The transmitted SATA number and the returned SA
In a mobile communication system, the phase difference between the two stations is measured and the communication line is monitored and the distance between the two stations is measured.
Control of a phase compensation circuit provided to the mobile station in order to compensate for phase errors occurring within the mobile station for SATA signals with different frequencies is controlled through the control line before setting up the communication line. SAT signal frequency W1 transmitted in advance
A phase compensation control method for a return signal, characterized in that the control is performed using m-separate codes.