JP3350002B2 - Mobile communication frequency stabilization system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication frequency stabilization system, and more particularly to a mobile communication frequency stabilization system for converging a transmission / reception frequency between a mobile station and a base station of a mobile communication system to a constant value.

[0002]

2. Description of the Related Art With the recent spread of mobile radios, communication between a plurality of mobile radios and between these radios and a base station is frequently performed within a certain radio area. If the frequency is not stable, communication becomes impossible due to frequency deviation, so it is necessary to stabilize the frequency.

FIG. 5 is a block diagram showing a conventional mobile communication frequency stabilizing system.

The conventional mobile communication frequency stabilizing system includes a mobile station 31 and a mobile station 3 existing in a base station area 30.
2. It has a mobile station 33 and a base station 34.

FIG. 6 is a flowchart showing an example of the operation of FIG.

Next, the operation will be described with reference to FIGS.

In the conventional system, as a means for stabilizing the frequency between mobile stations, each mobile station transmits a frequency F
1 downlink control signal. For example, the reference frequency B of the base station 34 is calculated from the frequency F1 of the downlink control signal received by the mobile station 31, and the reference frequency A of the mobile station 31 is compared with the reference frequency B of the base station 34, so that the mobile station 31
Is changed to F1 'and is approached to F1.
The mobile station 32 also compares the reference frequency C of the mobile station 32 with the reference frequency B of the base station 34, and sets the transmission / reception frequency of the mobile station 32 to F
Change to 1 '' and move closer to F1. When the mobile station 31 makes a call to the mobile station 32, the mobile station 31 transmits an uplink communication signal of a transmission frequency F1 '(F1 ≒ F1') to the base station 34, and the base station 34 , A downlink communication signal of frequency F1 is transmitted to enable communication, but the frequency is continuously corrected during the communication.

Similarly, the mobile station 33 compares the reference frequency D of the mobile station 33 with the reference frequency B of the base station 34, and changes the transmission / reception frequency of the mobile station 33 to F1 ′ ″ to approach F1. .

By performing the above operation, all the mobile stations in the base station area 30 receive the frequency F1 of the base station 34.
Follow. Therefore, the frequency in the base station area 30 can maintain a certain degree of stability. In any case, frequency correction is performed by AFC (Automatic Frequency).
y Control).

An example of such a technique is disclosed in Japanese Unexamined Patent Publication No.
A "wireless communication system" described in Japanese Patent No. 361434 is known.

In this publication, even if there is a frequency difference between a calling station and a called station in a TDMA / TDD wireless communication system, transmission and reception at the same frequency where mutual inconsistency in transmission and reception frequencies is eliminated by CPU control. A technique for performing the method is described.

[0012]

In the conventional mobile communication frequency stabilizing system described above, the frequency cannot be corrected unless the downlink signal from the base station is constantly received. In such a case, the frequency cannot be corrected.

Further, there is a disadvantage that the frequency pull-in time becomes long due to a large deviation of the reference voltage value from the subsequent re-input.

An object of the present invention is to move and stabilize the frequency of transmission and reception by averaging the frequency deviation between radio stations for each communication and reducing the deviation so as to stabilize the frequency of transmission and reception without always receiving radio waves. A communication frequency stabilization system is provided.

[0015]

SUMMARY OF THE INVENTION A mobile communication frequency stabilizing system according to the present invention includes a first mobile station, a second mobile station, and a base station, each of which is located within a communication area and has an initial transmission / reception frequency. The first mobile station has a first transmission / reception frequency X and a first deviation value A which is a deviation from a communication partner frequency, and the second mobile station has a second transmission / reception frequency Y And the second deviation value B, wherein the base station has a third transmission / reception frequency Z and a third deviation value C; wherein the first mobile station performs the first transmission / reception with respect to the second mobile station. The second mobile station having received the first transmission / reception frequency X directly performs communication with the frequency X; the second mobile station detects a deviation from the second transmission / reception frequency Y of the own station, and the second deviation value B The first transmission / reception frequency Y ′ reflecting the average deviation value D obtained from the averaging process with the first Direct communication with a mobile station and the base station to bring the frequency Y 'of the second mobile station closer to the frequency X of the first mobile station than the frequency Y, which is the previous stage; By setting a new deviation value E, the mobile station performs an operation using the transmission / reception frequency X ′ whose transmission / reception frequency is close to Y ′ with the first mobile station, the second mobile station, and the base station. The frequency used in the communication area is converged to a single value by repeating the steps between

A first mobile station, a second mobile station, a third mobile station, and a base station, each mobile station having an initial transmission / reception frequency within a communication area; Mobile stations and the base stations communicate with each other in a one-to-three communication, and when the first mobile station communicates with the second mobile station at a transmission frequency W, the third mobile station is not a direct communication partner. The mobile station and the base station receive the transmission / reception frequency W, and make the frequency of the own station approach the transmission / reception frequency W to correct the frequency to converge to a constant value frequency.

Each of the first, second, and third mobile stations and the base station includes a radio unit and a control unit.
A PLL (Phase (Phase)) which has a built-in voltage-controlled crystal oscillator and converts a reference voltage value from the control unit to a reference frequency and outputs the reference frequency.
A transmission system for transmitting, from a transmission antenna, a transmission signal obtained by mixing a transmission signal from the control unit and the reference frequency with a first mixer;
The received signal from the receiving antenna and the reference frequency are
And a receiving system for outputting a reception signal mixed by the mixer to the control unit, wherein the control unit detects a deviation from the reception signal mixed from the reception system with reference to the frequency of the own station. A detection circuit for outputting a deviation value; a storage device having a first register for storing an averaged average deviation value and a second register for storing the deviation value detected by the detection circuit; And an averaging circuit for outputting the average deviation value and the reference voltage value from the deviation value output and the average deviation value output from the storage device.

[0018]

[0019]

[0020]

[0021]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of a mobile communication frequency stabilizing system according to the present invention.

The present embodiment shown in FIG. 1 includes a mobile station 1, a mobile station 2, a base station 4 existing in a base station area 30, and a control console connected thereto. The control console is a console for operating the base station 4.

Referring to FIG. 1, mobile station 1, mobile station 2 and base station 4 communicate with one another. Also, mobile stations 1 and 2
And the base station 4 each have an initial transmission / reception frequency.
Indicates direct communication from the mobile station 1 to the mobile station 2. Mobile station 2
After the communication, the averaged deviation value D is reflected in the transmission / reception frequency, and control is performed so as to be closer to the transmission / reception frequency X of the mobile station 1.

Is a direct communication from the mobile station 2 to the mobile station 1,
Is a communication from the mobile station 2 to the base station 4, and each mobile station,
The base station performs the same operation as that described above, and controls the frequency of transmission and reception.

For example, it is assumed that the mobile station 1 has a transmission / reception frequency X set in advance and has a deviation value A which is a deviation from the frequency of a communication partner. Similarly, it is assumed that the transmission / reception frequency of the mobile station 2 is Y, the deviation value is B, the transmission / reception frequency of the base station 4 is Z, and the deviation value is C. The mobile station 1 directly communicates with the mobile station 2, and the frequency used at this time uses X which is the transmission / reception frequency of the mobile station 1.

The mobile station 2 having received the frequency X detects a deviation from the frequency Y of the mobile station, takes the average with the deviation value B, and stores the average as a new deviation value D in its own register. This is converted into a voltage value, which is used as a reference frequency of the mobile station 2 by a PLL circuit, and this is reflected on the transmission / reception frequency, and the new frequency is represented by Y ′.
The mobile station 2 performs communication. At this time, the frequency Y ′ of the mobile station 2 is closer to the frequency X of the mobile station 1 than at the previous stage of the frequency Y.

Next, the mobile station 2 communicates with the mobile station 1 at the transmission / reception frequency Y '. By performing the same operation as described above, the mobile station 1 moves the deviation value to E, reflects it on the transmission / reception frequency, and uses X ′ whose transmission / reception frequency approaches Y ′.

Basically, by repeating the above operation among the mobile station 1, mobile station 2, and base station 4, the frequency to be used is converged to one value.

Although the operation using a single frequency has been described, by operating the reference frequency of the wireless device, it is possible to operate the system with different transmission and reception frequencies for moving the transmission and reception frequencies.

FIG. 2 is a detailed block diagram showing a radio section and a control section of the mobile station / base station.

The mobile station and the base station use the same circuit for the radio section and the control section, respectively. The mobile station uses only the radio section and the control section, and the base station has only the radio section and the control section. An amplifier or the like (not shown) is added to the transmission line to increase the transmission output.

Referring to FIG. 2, the mobile station and the base station each include a control unit 11 and a radio unit 12,
The control unit 11 has a detection circuit 13, a storage device 14, and an averaging circuit 15, and the radio unit 12 has a PLL (Phase L
(locked Loop) circuit 16 and the PLL circuit 1
6, a voltage-controlled crystal oscillator 17, a transmission system 18 for transmitting a transmission signal 26, a reception system 19 for receiving a reception signal 25, and a transmission system mixer 10 for mixing the transmission signal 26 and a reference frequency 24. And a reception-type mixer 20 that mixes the reception signal 25 and the reference frequency 24.

The detection circuit 13 uses the frequency of its own station as a reference,
A deviation from the reception signal 25 received from the reception system 19 is detected, and a deviation value 21 is output. The storage device 14 has a register 41 for storing the averaged average deviation value 22 and a detection circuit 1.
3 stores a deviation value 21 detected from the detection circuit 13 for each communication, and a register 41 stores the average deviation value 22 calculated by the averaging circuit 15 for each communication. (This operation is cleared at regular intervals). Note that even if the power of the control unit 11 is turned off, the deviation value 21 stored in the registers 41 and 42 is not stored.
And the average deviation value 22 is not deleted.

FIG. 3 is a flowchart for explaining the operation of the present embodiment shown in FIG.

Next, the operation of this embodiment will be described in more detail with reference to FIG. 1, FIG. 2 and FIG.

First, the operation from the reception frequency in the mobile station and the base station in FIG. 2 to the change of the transmission / reception frequency of the own station will be described, and then the system operation in FIG. 1 will be described with reference to the flowchart shown in FIG.

It is assumed that a desired wave is always received for simplification of the description.

In FIG. 2, a reception system 19 receives a reception signal 25 from a communication partner. After the reception, the detection circuit 13 of the control unit 11 starts the operation of detecting the deviation value 21.
In detecting the deviation value 21, the phase of the received frequency is checked based on the frequency of the own station, and it is determined how much the phase is shifted.

In this manner, the degree of deviation is detected as a deviation value 21 of the frequency with respect to the communication partner based on the frequency of the own station. This deviation value 21 is stored in the register 4 of the storage device 14.
2 is stored. The history of the deviation value 21 for each communication is stored in the register 41 and the register 42 in the storage device 14. The averaging circuit 15 calculates the average value of the latest average deviation value output 27 stored in the register 41 and the deviation value output 28 stored in the register 42, and converts the averaged average deviation value 22 into a voltage value. Then, a process of outputting the reference voltage value 23 is performed. Further, the averaged deviation value 22 is stored as the latest data in the register 41 of the storage device 14.

The voltage controlled crystal oscillator 17 included in the PLL circuit 16 controls and outputs a reference frequency 24 based on the reference voltage value 23 converted in the averaging circuit 15. By supplying the reference frequency 24 to the mixer 10 of the transmission system 18 and the mixer 20 of the reception system 19, the frequency of transmission and reception can be controlled.

FIG. 3A shows a sequence immediately after power-on of the mobile station 1, the mobile station 2 and the base station 4.

The mobile stations 1 and 2 and the base station 4 each have a control unit 1
1 and a radio unit 12.

After the power is turned on, the mobile station 1 retrieves the initial deviation value A from the storage device 14. The voltage conversion of the initial deviation value A is performed, and the reference frequency 2
4 is generated, and the mixer 10 and 20 set the initial transmission / reception frequency X. The mobile station 2 and the base station 4 have the same sequence as described above.

That is, the mobile station 2 fetches the initial deviation value B from the storage device 14 after the power is turned on. This initial deviation value B
, A reference frequency 24 is generated by the PLL circuit 16 of the radio unit 12, and the initial transmission and reception frequency Y is set by the mixers 10 and 20.

After the base station 4 is turned on, the storage device 1
From 4, the initial deviation value C is taken. The voltage conversion of the initial deviation value C is performed, the reference frequency 24 is generated by the PLL circuit 16 of the radio unit 12, and the initial transmission and reception frequency Z is set by the mixers 10 and 20.

Assuming that a frequency shift of aging occurs in each mobile station and base station, mobile station 1
Is X = F + α, mobile station 2 is Y = F + β, and mobile station 3 is Z =
It is assumed that a transmission / reception frequency shifted by F + γ is set. However, there is a relationship of (α>β> γ).

FIG. 3B shows a sequence in which the mobile station 1 communicates with the mobile station 2. This corresponds to the operation of FIG. The mobile station 2 receives the transmission frequency X of the mobile station 1. From the transmission frequency X, the detection circuit 13 detects a deviation (α-β) from the frequency Y controlled to the initial deviation value B of the own station as described above.

Next, an average value with the initial deviation value B is obtained, and the average deviation value 22 as a new deviation value D is stored in the register 41 of the storage unit 14. The reference frequency 24 is controlled by supplying the voltage value obtained by converting the deviation value D to the voltage controlled crystal oscillator 17 of the PLL circuit 16, and the mixer 10,
At 20, the transmission / reception frequency is Y '= F + ε (α>ε>β>
γ). As a result, the transmission / reception frequency of the mobile station 2 is corrected and becomes closer to the transmission / reception frequency X of the mobile station 1.

FIG. 3C shows a sequence in which the mobile station 2 communicates with the mobile station 1. This corresponds to the operation of FIG. The mobile station 1 follows the same sequence as the mobile station 2 in the sequence of FIG. By controlling the reference frequency 24 by averaging the deviation values in this way, the transmission / reception frequency of the mobile station 2 can be changed to X ′ = F + φ (α>
φ>ε>β> γ). Thereby, the transmission / reception frequency of the mobile station 2 is corrected, and the frequency of the mobile station 1 and the frequency of FIG.
Will be even closer than after the sequence.

FIG. 3D shows a sequence in which the mobile station 2 performs communication with the base station 4. This corresponds to the operation of FIG. The base station 4 takes the same sequence as the mobile station 1 in the sequence of FIG. The mobile station 2 having the averaged deviation values sets the transmission / reception frequency to Z ′ = F + χ.
(Α>φ>ε>β>χ> γ). This allows
The transmission / reception frequency of the base station is corrected and becomes closer to the frequency of the mobile station 2 than after the operation of FIG.

Also, in FIG. 3E, even if the power of the mobile station 1 is once turned off, the storage device 14 turns on the power again so as to retain the history of the averaged deviation value 22 in the register 41. Even this prevents the mobile station 1 from deviating in frequency.

FIG. 4 is a block diagram showing a second preferred embodiment of the mobile communication frequency stabilizing system according to the present invention.

The present embodiment shown in FIG. 4 includes mobile station 1, mobile station 2, mobile station 3, and base station 4 existing in base station area 30.

In FIG. 4, components corresponding to those shown in FIG. 1 are denoted by the same reference numerals or symbols, and description thereof is omitted.

Referring to FIG. 4, although the basic configuration is as described above, one-to-n communication between mobile stations 1 to 3 and base station 4 is performed.
The communication of is further devised.

Is the first one-to-n communication in which the mobile station 1 communicates with the mobile station 2, the mobile station 3, and the base station 4. Therefore, it is a one-to-three communication. The frequency of transmission / reception after communication between the mobile station 2, the mobile station 3, and the base station 4 is corrected. And the same operation as above, wherein mobile station 2 communicates with mobile station 1, mobile station 3 and base station 4, and base station 4 communicates with mobile station 1, mobile station 2 and mobile station 3. This is the case.

It has been described that the mobile station and the base station on the receiving side detect the deviation between the frequency of the mobile station and the base station transmitting to the other station and the frequency of the own station, and correct the transmission and reception frequencies. A communication mode such as 1: n may be adopted. In this case, since there are a large number of mobile stations and base stations that receive in one communication, the averaging process is performed at a time, and the convergence to a frequency of a fixed value is achieved quickly.

The individual operations are the same as those in FIGS. 1 to 3, and a description thereof will be omitted.

Only the mobile station 1 transmits the frequency W to the mobile station 2.
In the case where the mobile station 3 and the base station 4 receive the frequency W and make the frequency close to the W, even the wireless station which is not the communication partner can receive the frequency and correct the frequency so that the convergence is achieved quickly. Can be.

As described above, the present system is composed of base station equipment that does not always transmit radio waves (hereinafter referred to as an emergency transmission base station) and mobile station equipment, and is provided between a base station and a mobile station or between mobile stations.
A mobile communication system capable of realizing communication between mobile stations (direct communication). Each mobile station and the base station perform a control to correct the transmission and reception frequencies for each communication so that the transmission and reception frequencies of the entire system are set to a fixed value. And a stable system can be realized.

As another means for stabilizing the frequency, there is a system composed of a base station equipment (hereinafter referred to as a normal transmission base station) for constantly transmitting radio waves and a mobile station equipment. In this case, the base station having higher accuracy than the mobile station always transmits a reference frequency to the mobile station, and the mobile station follows the frequency of the base station to stabilize the transmission / reception frequency.

However, it is difficult to use this means in a system configured as an emergency transmission base station because the base station does not always transmit radio waves. Also for the system, the transmission and reception frequency converges to one value by averaging the deviation of the mutual transmission and reception frequency for each communication and reducing the deviation by reflecting it on the transmission and reception frequency in the next communication, This makes it possible to stabilize the frequency.

In the present invention, simplex communication using different frequencies is used, but the present invention is not limited to this.
The transmission and reception frequencies may be the same or different transmission and reception frequencies.

[0065]

As described above, in the mobile communication frequency stabilizing system of the present invention, the above operation is repeatedly performed by each mobile station and the base station every time communication is performed, so that the mobile station and the base station can communicate with each other. Since the transmission / reception frequency shift becomes smaller and converges to one frequency, the transmission / reception frequency is a constant value even at the emergency transmission base station. It has the effect that it can be done.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a mobile communication frequency stabilization system of the present invention.

FIG. 2 is a detailed block diagram showing a radio unit and a control unit of a mobile station / base station.

FIG. 3 is a flowchart illustrating an operation of the exemplary embodiment of FIG. 1;

FIG. 4 is a block diagram illustrating a mobile communication frequency stabilization system according to a second embodiment of the present invention.

FIG. 5 is a block diagram showing a conventional mobile communication frequency stabilization system.

FIG. 6 is a flowchart illustrating an example of the operation of FIG. 5;

[Explanation of symbols]

 1, 2, 3 mobile station 4 base station 10 mixer 11 control unit 12 radio unit 13 detection circuit 14 storage device 15 average processing circuit 16 PLL circuit 17 voltage controlled crystal oscillator 18 transmission system 19 reception system 20 mixer 21 deviation value 22 average deviation Value 23 reference voltage value 24 reference frequency 25 reception signal 26 transmission signal 27 average deviation value output 28 deviation value output 30 base station area 31, 32, 33 mobile station 34 base station 41, 42 register

Claims (3)

(57) [Claims] 1. A present in the communication area, each first mobile station with an initial transmission and reception frequencies, and a second mobile station and the base station; first the first mobile station is a preset Deviation value A between the transmission and reception frequency X and the communication partner frequency
The second mobile station transmits a second transmission / reception frequency Y and a second deviation value B, and the base station transmits a third transmission / reception frequency Z
And the third deviation value C; wherein the first mobile station has the first deviation with respect to the second mobile station.
The second mobile station having received the first transmission / reception frequency X detects a deviation from the second transmission / reception frequency Y of the own station, and performs the second deviation. By directly communicating with the first mobile station and the base station at a new transmission / reception frequency Y ′ reflecting the average deviation value D obtained from the averaging process with the value B, the frequency Y ′ of the second mobile station is obtained. Is brought closer to the frequency X of the first mobile station from the frequency Y which is the previous stage; The first mobile station sets a new deviation value E,
The operation using the transmission / reception frequency X ′ with the transmission / reception frequency approaching Y ′ is repeated between the first mobile station, the second mobile station, and the base station, thereby using the communication area. A mobile communication frequency stabilization system characterized by converging a frequency to one value. 2. A present in the communication area, comprising a first mobile station with each initial transmission and reception frequencies, the second mobile station, and a third mobile station and a base station; the first, second, When a third mobile station and the base stations perform one-to-three communication, and the first mobile station communicates with the second mobile station at a transmission frequency W, the third mobile station is not a direct communication partner. 3. The mobile communication frequency stabilization system according to claim 3, wherein the mobile station and the base station receive the transmission / reception frequency W, and converge to a fixed value frequency by correcting the frequency of the own station to the transmission / reception frequency W. 3. The first, second, and third mobile stations and the base station each include a radio unit and a control unit, wherein the radio unit has a built-in voltage-controlled crystal oscillator, PLL that converts the reference voltage value of the signal to a reference frequency and outputs
(Phase Locked Loop) circuit; a transmission signal from the control unit and the reference frequency
A transmission system for transmitting a transmission signal mixed by the mixer from the transmission antenna from a transmission antenna;
And a receiving system for outputting a received signal mixed by the mixer of the present invention to the control unit. The control unit detects a deviation from the received signal mixed from the receiving system based on the frequency of the own station. A detection circuit for outputting a deviation value; a storage device having a first register for storing an averaged average deviation value and a second register for storing the deviation value detected by the detection circuit; An average processing circuit for outputting the average deviation value and the reference voltage value from the deviation value output and the average deviation value output from the storage device.