JPS5922424B2 - Multi-channel mobile station equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a multi-channel mobile station device that can communicate using any channel among all channels with a simple configuration in a mobile communication system using multiple channels such as train radio. It is related to.

Taking the train radio system of the Tokaido Shinkansen as an example of a mobile communication system using multiple channels, a mobile station device shown in the block diagram of FIG. 1 is mounted on a train and used.

In other words, a frequency conversion multiplexed radio link of channels CH1 to CH8 is used from a fixed station located at a predetermined distance to the mobile station, and a non-multiplexed radio link is used from the mobile station to the fixed station. These terminal telephones TEL1 to TEL5 on the train are used separately for operation command system and business public system, depending on the purpose of the terminal telephones TEL1 to TEL5.

Now, assuming that a call is made from a fixed station to a terminal telephone TELI in the same system via channel CH of the operation command system, an activation signal using a specific frequency is transmitted from the fixed station (not shown in the figure). This is received by the terminal equipment TE via the receiving antenna ANTR and the receiver RX, and is sent to the primary link L for system selection by the detection output of the internal signal receiver.
operates and connects the output of the terminal equipment TE to the call trunk TRKD.

Note that the call trunk TRKD is provided with a ringer RINGD for transmitting and receiving various control signals, and is used to transmit and receive signals regarding the completion of connection with the fixed station, as well as a secondary link LK for selecting terminal telephones TEL1, TEL, A calling signal is sent out via the terminal telephone TELl.
, TEL, the circuit between the fixed station and the mobile station is completed, and transmission from the mobile station is performed by the transmitter TX1 and the transmitting antenna ANTS1. however,
The transmission frequency of the transmitter TXl used at this time has a communication zone determined according to the section where the train is located, and the transmission frequency is selected according to this communication zone to prevent interference between communication zones. To prevent this, the transmitters TX, ~T
The transmission frequency of X3 is determined.

In addition, in the case of the Tokaido Shinkansen, the zone instruction signal is a train that uses a ground coil that has a resonant circuit with a specific resonance frequency installed on the track for each communication zone, and a pick-up coil that is installed on the car in the opposite area. The upper part detects the resonant frequency based on mutual electromagnetic coupling and receives the zone instruction signal. In addition, other channels CH, ~ CH8
The same applies when transmitters TX2 and TX3 are used, but the business public terminal telephone T used by the conductor and passengers
EL3 to TEL5 are received by channels CH to CH8 and simultaneously transmitted to transmitters TX2 and TX3.

Also, the primary link LKl is used in the same way, but the others are the secondary links LK,
is used. However, in the mobile station device with the above configuration, when the number of used channels increases further, the configuration of the terminal station device TE and the primary link LKl requires a capacity proportional to the number of used channels, and the device becomes large and heavy. This results in some disadvantages. Furthermore, it is extremely inappropriate as a mobile station device for line testing or as a portable mobile station device for use in the event of a disaster.

In other words, when a portable mobile station device for this purpose is constructed by applying the conventional method as is, and the number of channels used is tripled to 24, the block diagram shown in Fig. 2 will be obtained. Although there are only one terminal telephone TEL, the scale of the end station equipment TE and the primary link LKl is three times that of Fig. 1, and it is completely impossible to make it portable. become. The present invention has the purpose of eliminating all the drawbacks and requirements for miniaturization of the conventional technology, and provides multi-frequency signals for generating carrier signals for demodulation of end station equipment in addition to mobile stations in the mobile communication system described above. A signal generator, a fixed station designation signal sending circuit that sends out a fixed station designation signal based on the received zone designation signal, and a transmission control circuit that determines the transmission frequency are simultaneously controlled by one rotary switch, and the terminal station The present invention provides a multi-channel mobile station device that has a channel selection function added to the device itself and has an extremely simplified overall configuration.

The details of the present invention will be described below with reference to figures showing embodiments, but for the sake of convenience, the principle of multiplex demodulation in a terminal station device will be described first.

Figure 3 shows a situation in which a multiplexed signal is demodulated by frequency conversion. It is a frequency group having an occupied frequency band, and in this example, channels CHl to CHl2 exist as group A in 12 to 60 KHz, and 6
Channels CH1 to CH24 exist as group B in the frequency range of 0 to 108 KHz.

Therefore, if only the Af) A group is extracted using a splitter or the like, each of the channels CH1 to CH12 in B of the same figure will be 4.
They are arranged with an occupied frequency band of KHz, and if this is demodulated by a carrier wave signal SCl with a frequency of 120 KHz in a demodulator DMl and the frequency difference between each channel CHl to CHl2 and the carrier wave signal SCl is taken, the result is shown in FIG. As per Bf) 12KHz is 108KHzsB 60KHz
becomes \60KHz, and is converted to the same pace band as Af) Group B.

This is then converted into a demodulator DM2 as a first channel converter.
In this case, demodulation is performed using carrier wave signals SC2-1 to SC, -12 corresponding to the occupied frequency bands of each channel CHl to CHl2, and the frequency difference between them is extracted in the same manner as described above. Each channel CHl to CHl2 has the same occupied frequency band.

That is, taking channel CHl as an example, the occupied frequency band in C was 104 to 108 KHz, but by extracting the frequency difference with the frequency of carrier signal SC2-1, 156 KHz, 104 KHz becomes 156-104 = 52 KHz.
Therefore, 108KHz becomes 156-108=48KHz, and the other channels CH2 to CHl2 are also 48 to 5.
It is converted to an occupied frequency band of 2KHz. For example, in C, the original signal low frequency range of each channel CH, ~CH, 2 is on the high frequency side in the baseband, whereas in D, the original signal low frequency range is on the low frequency side of the occupied frequency band. , so that complete demodulation (by the subsequent frequency shift down operation) is performed.

That is, in the demodulator DM3 as the second speech path converter, a carrier wave signal SC3 having a common frequency of 48 KHz is used for each channel CHl to CHl2, and by frequency difference extraction similar to the above, each channel CHl
~CH12 becomes an occupied frequency band of 0 to 4 KHz, and at the same time, the frequency of the original signal is reproduced as it is.

In addition, group B in A is the same as \60~108KHz9
Since it is a baseband signal, it is demodulated in the same way as the A group by the operation after the demodulator DM2.

In addition, when using each channel CHl to CHu at the same time, the circuit after demodulator DM2 is used for each channel CHl to CHu.
24 respectively. Figure 4 shows
FIG. 2 is a block diagram showing an embodiment of the present invention constructed based on the above principle, in which a receiving antenna ANTR and a receiver RX
The received signals from the fixed station corresponding to A in FIG. 3 received via the branch circuit DVl using a branching filter etc.
4, and signal circuits such as amplifiers SCl, S
Given to C2.

Note that when a three-turn transformer branch resistor network or the like is used in the branch circuit DVl, an f-wave device that passes only the A group or the B group is added to each signal circuit SC, SC2. The output of the signal circuit SCl is demodulated into the signal shown in FIG. 3C in a demodulator DMl similar to that shown in FIG.
It is applied to the switching circuit SW via a branch circuit DV2 similar to V.

In the example shown in Fig. 4, the zone designation signal is not transmitted from the ground transceiver, but from the fixed station as a signal using a specific frequency in the baseband), and the branch circuit D3 similar to the branch circuit DVl) is transmitted from the fixed station as a signal using a specific frequency in the baseband. This zone designation signal is received by either of the receiving circuits RECl or REC2 via the mobile station, and it is detected in which communication zone the mobile station is currently located.

The one in Figure 1 uses a wireless line based on space waves, while the one in Figure 4 uses guided radio via an attached cable, which is less likely to cause interference than with spatial waves. Therefore, the number of frequency types used for the zone designation signal, which is made to vary for each communication zone, may be small.For example, it is sufficient to alternately use different frequencies.For this reason, in the example shown in Fig. 4, the zone designation signal is There are two types. However, if the types of zone designation signals increase depending on the conditions, it goes without saying that the receiving circuits RECl and REC2 will be added accordingly. The switching circuit SW is given a group B signal from the signal circuit SC2 as the other input, and if the relay contact shown as an example of the configuration of the switching circuit SW is on the a side, the signal of the group A is given, and if it is on the b side, the signal of the group B is given. The signal is sent out as its output, completely demodulated via demodulators DM2, DM, similar to FIG. 3, and then applied to the terminal telephone TEL by means of the speech trunk TRK with the addition of the ringer RlNG.

In addition, a telephone trunk TRK equipped with a 2-wire 4-wire conversion circuit, etc.
The transmission output from the transmitter TX is applied to the modulation input of the transmitter TX and is transmitted by the transmitter TXl transmitting antenna ANTS as a predetermined frequency to the fixed station.

However, since a large number of channels CH1 to CH2 are prepared as transmission frequencies, the frequencies of the channels are close to each other, and when interference occurs with other mobile stations at the receiver on the fixed station side. As a countermeasure, a specific audio frequency signal determined by the zone designation signal and the channel to be used is generated and transmitted in the fixed station designation signal sending circuit SG.This signal is also transmitted from the transmitter TX, and is transmitted at the fixed station side. After detecting this signal, line configuration is performed. In addition,
In order to be used as a portable device for examinations or disasters, there is only one terminal telephone TEL, and channels CH1 to C
Since it is only necessary to select and use one of H24, a rotary type switch RS is provided to select the channel to be used. It is designed to be given to each circuit that receives specified input, and the transmitter control circuit T is transmitted by the rotor RS-1.
After specifying the channel to be used for C, transmitter control circuit T
The transmission frequency of the transmitter TX is determined based on the control of the transmitter C. In addition, in rotor RS-2, the switching control circuit SWC is designated with the channel to be used, and switching control is performed so that the switching circuit SW is on the b side for channels CHl to CHl, and the switching circuit SW is on the b side for channels CHl to CH24. The circuit SWC controls the switching circuit SW.

On the other hand, the rotor RS-, sends demodulating carrier wave signals SCl, SC2-1 to SC2-12, to each demodulator DMl to DM,
By controlling the multi-frequency signal generator MFG which provides SC3, in particular, by operating the rotor RS-, the channels CH1 to C
Carrier wave signal SC2-1~ with a frequency determined according to H, .
One of SC2-12 is generated.

That is, the frequencies of the carrier signals SCl, Sc, in this case are 120 KHz for the former and 48 KH for the latter, as in FIG.
z has a constant frequency, whereas the carrier wave signal SC2 has a constant frequency of 1 as shown in FIG.
Any frequency between 12 and 1-56 KHz is defined. Similarly, the rotor RS is connected to the fixed station designation signal sending circuit S.
A channel designation input is given to G, and the receiving circuit RECl
Alternatively, a fixed station designation signal having a frequency based on a combination of the output of the REC and the channel designation input is generated. Therefore, by operating the rotary switch RS to specify the channel to be used, the predetermined frequency is determined for both the reception channel and the transmission channel, and the fixed station designation signal is also determined based on the received zone designation signal. The channel corresponding to the used channel is transmitted, and the ringer RING sends and receives various signals to the terminal telephone TE via the call trunk TRK.
The line configuration between L and the partner fixed station is completed, and communication between the two is performed.

Incidentally, as the multi-frequency signal generator MFG, each individual oscillation circuit may be provided and switched for the carrier wave signal SC2, but
It is preferable to provide an oscillation circuit controlled by an automatic phase control loop for the signal SC2, and set the oscillation frequency by a counter whose frequency division ratio is determined by a channel designation input.

That is, a detailed block diagram of the multi-frequency signal generator MFG is shown in FIG.
Create a reference signal for z and apply it to one input of the phase comparator PCP, and also output the output of the voltage controlled oscillator VCO to the programmable counter PCTl and the frequency divider DIV2.
The frequency is divided by and applied to the other input of the phase comparator PCP,
If the voltage controlled oscillator VCO is controlled by the output of the phase comparator PCP via the low-frequency f wave generator LPF, an automatic phase control loop is configured, and by changing the frequency division ratio of the programmable counter PCTl, the voltage controlled oscillator The oscillation frequency of the VCO also changes. Therefore, if the ground air applied via the rotor RS- is used as a channel specified input, and this is converted into the control input of the programmable counter PCTl by the coater CODl, and the frequency division ratio of the counter PCTl is determined, A carrier wave signal SC2 having a frequency corresponding to a predetermined channel can be generated. In the case of the same figure, the carrier wave signal SC2 is 156 KHz for channels CH1 and CH24, and the carrier wave signal Sc is 112 KHz for channels CH12 and CH13. Therefore, the output of the voltage controlled oscillator CO is 224 to 312K.
Hz, and when the division ratio of frequency divider DIV2 is expressed as %,
The frequency division ratio of the programmable counter PCTl may be determined according to a predetermined channel within the range of %r%.Furthermore, the other carrier signals SCl, SC may also be set using a frequency divider DIV with a fixed frequency division ratio.
4, DIV5, the clock pulse Pc is frequency-divided and generated.

FIG. 6 is a detailed block diagram of the fixed station designation signal sending circuit SG. Similarly to FIG. However, in this case, depending on the zone where the train exists, it is 3.4 to 4.
Since a predetermined frequency is selected from 6 frequencies within 15 KHz, the channel designation input given via the rotor RS-4 and the outputs of the receiving circuits RECl and REC2 are ANDed.
Gate circuit GAT using a circuit or matrix circuit, etc.
After the combination processing is performed via the coater COD2, the signal is converted into a control input of the programmable counter PCT2, and the frequency division ratio of the counter PCT2 is determined.

Depending on the required frequency stability of the fixed station designation signal, an automatic phase control loop similar to that shown in Figure 5 may be used, in which a large number of oscillators are prepared and their outputs are selected by the channel designation input. Although the same applies, the one shown in FIG. 6 is preferable because it has a simple configuration.

As is clear from the above explanation, according to the present invention, compared to the case where the conventional configuration is applied as is, the configuration of the terminal equipment is greatly simplified, and connection links are no longer required, making the entire structure compact. Moreover, it becomes easy to reduce the weight.

In addition, since the channels to be used are determined at once by operating the rotary switch, handling is extremely simple, and a great effect can be obtained as a mobile station device for testing in mobile communication systems, for use in times of disaster, etc. It goes without saying that the detailed configuration may be determined through various modifications or selections depending on the conditions of the mobile communication system.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a conventional mobile station configuration, Fig. 2 is a block diagram of a test mobile station with a conventional configuration, Fig. 3 is a diagram showing the demodulation principle of a frequency conversion multiplexed signal, and Fig. 4 is a block diagram showing a conventional mobile station configuration. FIG. 5 is a block diagram showing details of a multi-frequency signal generator, and FIG. 6 is a block diagram showing details of a fixed station designation signal sending circuit. RS...Rotary type switch (channel designation input),
MFG...Multi-frequency signal generator, DM2...
..., demodulator, RECl, REC2...reception circuit, SG...fixed station designation signal transmission circuit, TC
......Transmitter control circuit, SC2...Carrier signal, PCTl, PCT2...Programmable counter, PCP...Phase comparator, VCO
...Voltage controlled oscillator, CODl, COD2...
...Coater, GAT...Gate circuit.

Claims (1)

[Claims] 1. In a mobile station of a mobile communication system in which a frequency conversion multiplexed radio link is used from a fixed station to a mobile station, and a non-multiplexed radio link is used from a mobile station to a fixed station, a multi-frequency signal generator that generates a carrier signal for demodulation; and a demodulator that uses the output of the multi-frequency signal generator to convert a frequency group having different occupied frequency bands for each channel in the baseband into the same occupied frequency band. and a fixed station designation signal sending circuit that sends out a fixed station designation signal determined by the received zone designation signal and the channel designation input, and a transmitter control circuit that determines a transmission frequency based on the channel designation input. A multi-channel mobile station device. 2. Claim 1, characterized in that a multi-frequency signal generator is used in which the oscillation frequency controlled by the automatic phase control loop is set by a counter with a division ratio determined by a channel designation input. multi-channel mobile station equipment. 3. A fixed station designation signal transmission circuit is used which divides the original oscillation frequency and generates a fixed station designation signal using a counter whose frequency division ratio is set by a combination of a zone designation signal and a channel designation input. A multi-channel mobile station device according to claim 1.