JPH06244782A - Radio transmitter-receiver and mobile communication system - Google Patents

Abstract

PURPOSE:To prevent communication from being inadvertently cut off when a mobile station is tentatively hidden behind a building or the like and a reception level tentatively declines. CONSTITUTION:A GPS antenna 11-a position detection circuit 13 detect the longitude and latitude of the mobile station based on radio waves from plural GPS satellites. A distance calculation circuit 25 calculates a distance to a base station based on the latitude/longitude information of the base station and the latitude/longitude information of the mobile station and a level detection circuit 22 detects the level of reception signals received by a transmission/ reception antenna 21. A control circuit 26 detects a block state based on the reception level and the distance to the base station and also controls a fixed time which is the threshold value of the time when the reception level declines defined as conditions for cutting off the communication so as to be long in the block state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile station wireless transceiver and base station wireless transceiver.

[0002]

2. Description of the Related Art A mobile communication system wirelessly communicates with a moving body such as an automobile, a ship, or an aircraft. When the strength (level) of the received signal is detected and the received level decreases and a signal of a specific frequency cannot be detected, or when valid frames cannot be continuously received,
A so-called communication protocol (communication control procedure) for terminating (disconnecting) communication is provided. This is a protocol assuming a case where the mobile station moves away from the service area of the base station and communication cannot be continued.

[0003]

By the way, even if a mobile station is actually located at a distance (within a service area) where it can sufficiently communicate with a base station, the mobile station is temporarily hidden behind a building or the like. Then, the reception level is lowered in each of the base station and the mobile station, and the communication is disconnected as in the case where the mobile station is out of the service area of the base station. Therefore, in the conventional device, a communication protocol is used that disconnects the communication for the first time when the reception level continues to decrease for a predetermined time or when a predetermined number of invalid frames are detected continuously. The communication protocol is still unable to distinguish whether the mobile station is out of the service area or hidden behind a base station, and there is a problem that the communication is inadvertently disconnected.

Further, in a mobile communication system adopting a so-called spread spectrum communication system, in order to solve the so-called near-far problem, the power of a transmission signal transmitted from a mobile station is controlled so that each mobile station received by a base station. We must ensure that the received power from the is uniform. However, for example, when a mobile station in the shadow makes a call and then escapes from the shadow,
There is a problem that the mobile station transmits at a power larger than the originally required transmission power when the mobile station temporarily hides in the shadow of a call and then escapes.

The present invention has been made in view of such circumstances, and a call is not accidentally disconnected, and in a mobile communication system adopting a spread spectrum communication system, transmission from a mobile body is performed. It is an object of the present invention to provide a mobile station radio transceiver, a base station radio transceiver, and a mobile communication system that can control power more accurately than conventional devices.

[0006]

In order to solve the above-mentioned problems, a first mobile station radio transmitter / receiver according to the present invention comprises a position detecting means for detecting latitude and longitude and a base station radio transmitter / receiver. Based on the transmitted latitude and longitude information of the base station and the latitude and longitude information from the position detection means, a distance calculation means for calculating the distance to the base station, a quality detection means for detecting the quality of the received signal, and a distance calculation A control means for controlling the communication protocol based on the distance information from the means and the quality of the received signal from the quality detection means.

The base station radio transmitter / receiver according to the present invention further comprises distance calculating means for calculating the distance to the mobile station based on the latitude / longitude information of the mobile station sent from the mobile station radio transmitter / receiver. A quality detecting means for detecting the quality of the received signal and a control means for controlling the communication protocol based on the distance information from the distance calculating means and the quality of the received signal from the quality detecting means are provided.

Further, the mobile communication system according to the present invention is
It is characterized by comprising the first mobile station radio transceiver and the base station transceiver.

A second mobile station radio transmitter / receiver according to the present invention is the first mobile station radio transmitter / receiver using a spread spectrum communication system, wherein the control means is a distance from the distance calculation means. It is characterized in that the communication protocol is controlled and the transmission power is controlled based on the information and the quality of the received signal from the quality detecting means.

A third mobile station radio transmitter / receiver according to the present invention is the same as the first mobile station radio transmitter / receiver.
Notifying means for notifying deterioration of the received signal when the distance to the base station is within a predetermined range and the received signal deteriorates based on the distance information from the distance calculating means and the quality of the received signal from the quality detecting means. It is characterized by including.

[0011]

In the mobile station radio transmitter-receiver according to the present invention, the distance to the base station is calculated based on the latitude and longitude information of the mobile station and the latitude and longitude information of the base station, and the distance information and the quality of the received signal are calculated. Based on this, the communication protocol is controlled.

Further, in the base station radio transmitting / receiving apparatus according to the present invention, the distance to the mobile station is calculated based on the latitude / longitude information of the mobile station and the latitude / longitude information of the base station, and the distance information and the received signal are calculated. Control the communication protocol based on the quality.

Further, in the mobile station radio transmitting / receiving apparatus according to the present invention, the communication protocol and the transmission power are controlled based on the distance information to the base station and the quality of the received signal.

Further, in the mobile station radio transmitter-receiver according to the present invention, when the distance to the base station is within a predetermined range and the received signal is deteriorated, based on the distance information to the base station and the quality of the received signal. Then, the user is notified of the deterioration of the received signal.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a wireless transceiver for mobile stations and a wireless transceiver for base stations according to the present invention will be described below with reference to the drawings. In this embodiment, the present invention is applied to a mobile station radio transmitter / receiver adopting a so-called spread spectrum communication system, and FIG. 1 is a block diagram showing a concrete circuit configuration of the mobile station radio transmitter / receiver. Is. Since the base station wireless transceiver also has the same function as this mobile station wireless transceiver, a block diagram showing the circuit configuration is omitted.

The mobile station radio transmitter / receiver of this embodiment is
As shown in FIG. 1, so-called GPS (Global Positioning S
ystem) GPS antenna 11 for receiving radio waves from satellites
And a GPS demodulation circuit 12 that reproduces a time signal by performing processing such as demodulation on the received signal received by the GPS antenna 11, and the latitude and longitude of the mobile station based on the time signal from the GPS demodulation circuit 12. Position detection circuit 13 for detecting information
And a transmission / reception antenna 21 and a level detection circuit 22 for detecting the quality of a reception signal received by the transmission / reception antenna 21.
A demodulation circuit 23 that reproduces the received data by performing processing such as demodulation on the received signal supplied through the level detection circuit 22, and the latitude and longitude information of the base station from the received data reproduced by the demodulation circuit 23. Reception information processing circuit 2 for detecting
4, a distance calculation circuit 25 for calculating the distance to the base station based on the latitude / longitude information of the mobile station from the position detection circuit 13 and the latitude / longitude information of the base station from the reception information processing circuit 24; Based on the distance information from the distance calculation circuit 25 and the quality of the received signal from the level detection circuit 22,
A control circuit 26 for controlling a so-called communication protocol (communication control procedure) and the like, a display circuit 27 for notifying a user of a block state described later, and transmission information processing for adding the latitude and longitude information of the mobile station to the transmission information. The circuit 31 includes a modulation circuit 32 that performs processing such as modulation on transmission data from the transmission information processing circuit 31, and an output amplifier 33 that amplifies a modulation signal from the modulation circuit 32.

Then, for example, after a traffic channel for communication is established with the base station according to a predetermined communication protocol, it is converted into a digital signal by a user by an analog / digital converter (not shown). The audio signal or the like is supplied as transmission information to the transmission information processing circuit 31 via the terminal 34. The transmission information processing circuit 31 adds the latitude / longitude information of the mobile station detected by the position detection circuit 13 and a control signal for controlling, for example, a call to the transmission information, and the obtained transmission data is modulated by the modulation circuit. Supply to 32. The modulation circuit 32 spreads the spectrum of the transmission data, performs a predetermined modulation, and supplies the obtained modulation signal to the output amplifier 33. The gain of the output amplifier 33 is controlled by the control circuit 26 based on the level of the received signal, and the modulated signal is amplified by the output amplifier 33 so that the level received by the base station becomes constant. It is adapted to be transmitted to the base station via the transmitting / receiving antenna 21.

On the other hand, for example, the voice signal of the other party is sent to the demodulation circuit 23 as a reception signal via the transmission / reception antenna 21 and the level detection circuit 22, together with latitude / longitude information of the base station, a control signal for controlling a telephone call and the like. Supplied. The demodulation circuit 23 performs predetermined demodulation processing on the received signal, performs code synchronization (spectrum despreading), and supplies the obtained received data to the reception information processing circuit 24. The reception information processing circuit 24 separates the latitude and longitude information of the base station from the received data and supplies the separated latitude and longitude information of the base station to the distance calculation circuit 25. The remaining audio signal data is digitally received as reception information via the terminal 28.
It is supplied to an analog converter (not shown) and converted into an audio signal.

Thus, a telephone call is made using this mobile station radio transmitter / receiver. In addition, this mobile radio transmitter / receiver detects the quality of a received signal, for example, the strength (level) of the received signal, and when a signal of a specific frequency cannot be detected due to a decrease in the received level, or when continuously valid frames are detected. When the mobile station is within the service area of the base station based on the distance between the base station and the mobile station when it is unable to receive, the control for relaxing the communication protocol adopted by the conventional device to terminate the communication is performed. By doing so, the call can be maintained even if the mobile station is temporarily hidden behind a building or the like.

Specifically, the GPS antenna 11 receives radio waves including highly accurate time signals from a plurality of GPS satellites, and the GPS demodulation circuit 12 performs processing such as demodulation on the received signal received. Then, the time signal is reproduced and this time signal is supplied to the position detection circuit 13.

The position detection circuit 13 calculates the distance to each GPS satellite based on the time signal, and detects the latitude and longitude of the mobile station, which is obtained as the intersection of the spherical surface from the absolute position of each satellite, with the distance as the radius. To do. Then, the latitude / longitude information of the mobile station is supplied to the distance calculation circuit 25.

As described above, the latitude / longitude information of the base station is also supplied to the distance calculation circuit 25. Based on the latitude / longitude information of the base station and the latitude / longitude information of the mobile station, the distance calculation circuit 25 Calculate the distance to the base station.

On the other hand, the level detection circuit 22 detects the quality of the reception signal received by the transmission / reception antenna 21, for example, its level, and supplies the detected reception level to the control circuit 26.

Based on this reception level and the distance to the base station supplied from the distance calculating circuit 25, the control circuit 26 determines that the mobile station is within the service area of the base station as shown in Table 1 below. Then, a state where the reception level is lowered (hereinafter referred to as a block state) is detected.

[0025]

[Table 1]

That is, when the mobile station is within the service area and the reception level is high, it is the first normal state,
When the reception level is low, the mobile station is out of the service area, and when the reception level is low, it is the second normal state. When the reception level is high, an erroneous signal is received. It is in a state of being.

Then, the control circuit 26 controls the communication protocol in the block state, and specifically, for example, a predetermined time which is a threshold value of the time when the reception level is lowered, which is a condition for disconnecting communication (call). The mobile station is controlled to be longer than in the second normal state where the mobile station is out of the service area and the reception level is low. By the way, the control for increasing the predetermined time, which is the threshold value for detecting the block state and disconnecting the communication, is also performed in the base station wireless transmission / reception device having the same circuit configuration as the mobile station wireless transmission / reception device. As a result, for example, it is possible to prevent the mobile station from being temporarily hidden behind a building or the like and being inadvertently disconnected from the communication when the reception level is temporarily reduced. Although the block state is detected based on the reception level in the above specific example, the block state is detected based on, for example, the number of consecutive invalid frames,
The threshold value of the number of frames in this block state may be controlled to be larger than the threshold value in the second normal state. Further, for example, when the mobile station is in the service area based on the temporal change of the reception level and the reception level sharply decreases, the blocking state may be set.

Further, the control unit 26 controls the output amplifier 33 in the block state so that the gain becomes a value immediately before entering the block state, for example. As a result, the mobile station is hidden behind the object and the reception level is lowered, so that the gain of the output amplifier 33 is increased, and it is possible to prevent transmission with excessive power to the base station when the mobile station escapes from the object. .

Further, the control section 26 displays on the display circuit 27 that the block state has been reached to notify the user. As a result, the user cannot make a call,
It is possible to know that the communication is not broken. Note that the block state may be notified by sound, for example.

It is needless to say that the present invention is not limited to the above-mentioned embodiments, but can be applied to, for example, an analog type wireless transmitting / receiving apparatus.

[0031]

As is apparent from the above description, in the radio transmitter / receiver according to the present invention, the distance between the base station and the mobile station is calculated based on the latitude / longitude information of the mobile station and the latitude / longitude information of the base station. However, based on the distance information and the quality of the received signal, the communication protocol, for example, when the mobile station is within the service area of the base station, relaxes the communication protocol adopted by the conventional device to terminate the communication. By performing the control, for example, it is possible to prevent the communication from being disconnected when the mobile station is temporarily hidden behind an object such as a building and the reception level is temporarily lowered.

In the mobile station radio transmitter-receiver according to the present invention, the transmission power is controlled based on the distance information to the base station and the quality of the received signal, so that the mobile station is hidden behind the object and the reception level is reduced. Is decreased, the gain of the output amplifier is increased, and it is possible to prevent transmission with excessive power to the base station when the user escapes from the shadow.

Further, in the mobile station radio transmitter-receiver according to the present invention, when the distance to the base station is within a predetermined range and the received signal deteriorates based on the distance information to the base station and the quality of the received signal. In addition, by notifying the user of the deterioration of the received signal, the user can know that the communication is not disconnected.

[Brief description of drawings]

FIG. 1 is a block diagram showing a specific circuit structure of a mobile station radio transceiver apparatus to which the present invention is applied.

[Explanation of symbols]

 11 ... GPS antenna 13 ... Position detection circuit 21 ... Transmission / reception antenna 22 ... Level detection circuit 24 ... Reception information processing circuit 25 ... Distance calculation circuit 26 ... Control circuit 27 ... Display circuit 31 ... Transmission information processing circuit 33 ... Output amplifier

Claims (5)

[Claims] 1. A position detecting means for detecting a latitude and a longitude; a latitude / longitude information of the base station sent from a radio transmitting / receiving device for a base station; and latitude / longitude information from the position detecting means to a base station. , A quality detecting means for detecting the quality of the received signal, and a communication protocol is controlled based on the distance information from the distance calculating means and the quality of the received signal from the quality detecting means. A wireless transmitting / receiving apparatus for a mobile station, comprising: a control unit. 2. A distance calculating means for calculating a distance to the mobile station based on latitude / longitude information of the mobile station transmitted from the mobile station radio transmitting / receiving device, and a quality detecting means for detecting quality of a received signal. A base transceiver station radio transmitter / receiver, comprising: control means for controlling a communication protocol based on the distance information from the distance calculating means and the quality of a received signal from the quality detecting means. 3. A mobile communication system comprising: the mobile station radio transceiver apparatus according to claim 1; and the base station transceiver apparatus according to claim 2. 4. The mobile station radio transmitter-receiver according to claim 1, wherein a spread spectrum communication system is used, wherein the control means includes distance information from the distance calculation means and a received signal from the quality detection means. A wireless transceiver device for a mobile station, which controls a transmission protocol as well as a communication protocol based on quality. 5. The received signal when the distance to the base station is within a predetermined range and the received signal deteriorates based on the distance information from the distance calculating means and the quality of the received signal from the quality detecting means. 2. The mobile station radio transceiver apparatus according to claim 1, further comprising a notifying unit for notifying deterioration of the.