JPH09247075A - Method for detecting reception field intensity in multi-channel access radio system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a control signal and a carrier and to detect field intensity when a moving radio station waits in a control channel if the control signal and the carrier, which are transmitted from a radio base station, are transmitted at a long interval period and to provide precise reception field intensity for in-area judgment at the time of executing the in-area judgment. SOLUTION: In the radio system of a multi-channel access system which is constituted of a radio base station for controlling a communication line and the moving radio station executing communication in accordance with the control of the radio base station, the control signal 2 whose one part is constituted of a frame synchronizing signal 7 and the carrier 1 are transmitted from the radio base station to the moving radio station at a control channel, the control signal 2 and the carrier 1 are received and detected in the moving radio station and the intensity of reception field is detected with the carrier level of a signal period following the frame synchronizing signal 7 of the control signal 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-channel access (hereinafter referred to as MCA) type wireless system, and a reception electric field in a mobile wireless station which is waiting for a control channel transmitted from a wireless base station. The present invention relates to improvement of the intensity detection method.

[0002]

2. Description of the Related Art In a wireless system based on the MCA system, generally, a wireless base station controls the control of a communication line, and the control of the communication line is usually assigned exclusively for communication of control signals for line control. Is being done in the channel. In such a radio system based on the MCA method, a mobile radio station at the time of standby receives the control channel transmitted from the radio base station and always waits in the control channel reception state. When starting communication, the mobile radio station exchanges various line control information such as line availability on the control channel and designation of the call channel with the radio base station, and then switches to the designated call channel to make a call. enter. In the MCA radio system, whether the mobile station is in the MCA radio system area, that is, within the service area of the radio base station while the mobile radio station is waiting for the control channel. The function of determining (hereinafter, referred to as in-range determination) is required.

Generally, as means for making an in-range judgment,
A means for making an area determination by detecting a control signal transmitted from the radio base station on the control channel, a means for making an area determination by the electric field strength of the carrier of the received control channel, and the like are used. The means for determining the area by detecting the control signal transmitted on the control channel is the control transmitted by the control channel when the mobile radio station is waiting for the control channel transmitted from the radio base station. A signal is received, but it is judged whether the received control signal is a control signal of the MCA wireless system to which the own station belongs, and M
It is to judge whether or not the CA wireless system exists. Further, the means for judging by the received electric field strength of the carrier of the received control channel judges whether or not the strength of the radio wave received while waiting for the control channel is sufficient to satisfy the communication quality. It is a thing. Note that normally, when the logical product of the above two determination results is established, it is determined to be within the range.

The conventional means for determining the area in the MCA radio system will be specifically described below. First, in the conventional MCA radio system, an example of a connection procedure of a communication line in a control channel between a radio base station and a mobile radio station, for example, a connection operation procedure when a mobile radio station calls a radio base station is shown in FIG. , And will be described. The radio base station constantly transmits the control signal 103 on the control channel 101, and the control signal 103 is for notifying the status of the line and various information in the MCA radio system. The mobile radio station is in the standby state and receives the control signal 103 transmitted from the radio base station on the control channel 101. When a mobile radio station calls a radio base station,
Line connection request signal 1 to wireless base station via control channel 101
04 is transmitted. The radio base station receives the line connection request signal 104 from the mobile radio station, transmits the call channel designation signal 105 to the mobile radio station if the call channel is available and line connection is possible, and the radio base station , Switch the channel to the call channel 102. When the mobile radio station receives the call channel designation signal 105 from the radio base station, the mobile radio station switches the channel to the call channel 102 and starts a call 106 with the radio base station.

As described above, the mobile radio station receives the control signal 103 transmitted from the radio base station on the control channel 101 in the standby state. At this time, the content of the control signal 103 and the signal reception time are received. The electric field strength is analyzed to determine whether or not the own station is within the system area, which is the service area of the MCA wireless system. FIG. 4 shows a schematic block diagram relating to the area determination of the receiving device of the mobile radio station, and a conventional example of the area determination will be described. In the mobile radio station, the receiving unit 1 receiving the transmission signal from the radio base station
A reception demodulation output signal and a reception electric field strength detection voltage (hereinafter referred to as RSSI) are output from 0, one reception demodulation output signal is input to the control signal detection unit 13, and the reception control signal from the control signal detection unit 13 is input. Is output to the central processing unit 12. The other RSSI voltage is input to the A / D converter 11, and the sampling output data is output from the A / D converter 11 to the central processing unit 12.

One of the reception demodulation output signals output from the reception unit 10 is an analog signal, but the control signal detection unit 1
A control signal is detected in 3 and is input to the central processing unit 12 as a reception control signal of a digital signal and used for data analysis. The other RSSI voltage is an output obtained by detecting the carrier level of the reception signal received by the receiving unit 10 and converting the detection output into a DC voltage.
It is sampled in the / D converter 11, converted into digital data, and compared with a preset reference value in the central processing unit 12. Here, the reference value set in advance in the central processing unit 12 is the reception electric field strength that can sufficiently secure the call quality, for example, A / D conversion data of the RSSI voltage corresponding to the reception level when the reception reference sensitivity is input. It was done.

In the receiving section configured as described above, the range determination is performed as described below. Furthermore, in addition to FIG. 4, description will be given using the signal timing explanatory diagram shown in FIG. The radio base station always continuously transmits the control signal transmission carrier 21 on the control channel, and additionally transmits the control signal 22 at a constant cycle. On the other hand, the mobile radio station, while waiting for the reception of the control channel,
The control signal transmission carrier 21 transmitted by the wireless base station is constantly received, and the reception unit 23 (see FIG. 4) obtains the reception carrier 23. From this reception carrier 23, the RSSI
A voltage 24 is being generated. RSS generated in the receiving unit 10
The I voltage 24 is input to the A / D converter 11 and converted into sampling output data (digital data) sampled by the sampling signal 25 having a constant cycle. Further, the control signal 22 received together with the control signal transmission carrier 21 is analyzed by the central processing unit 12 to determine whether it is the control signal of the MCA wireless system to which the own station belongs. If there is, it is determined to be within range. On the other hand, the sampling output data obtained by converting the RSSI signal 24 into digital data is the central processing unit 1
In 2, the average value for a certain period is calculated, the average value is compared with the reference value, and if the received carrier level is higher than the received electric field strength that can sufficiently secure the call quality, it is determined to be within the range. The analysis result of the control signal and the determination result of the received electric field strength are monitored at regular intervals, and the determination result is updated.

[0008]

According to the received electric field strength detection method in the conventional MCA radio system, the control signal transmission carrier transmitted by the radio base station in the control channel is continuous transmission, or transmission is performed even if it is not continuous. If the cycle is very short and is close to continuous transmission,
The mobile radio station can perform the area determination based on the electric field strength by constantly sampling the RSSI voltage at a constant cycle, but the control signal transmission carrier is transmitted at a very long interval from the control signal transmission cycle from the radio base station. If it is also sent with this, the following problems occur. When the RSSI voltage is constantly sampled at a constant cycle, the result is averaged every several samplings, and the in-range determination is made based on this data, the received electric field strength is measured during the period in which the control signal is transmitted from the wireless base station.
Since the RSSI signal is sampled even during the period when there is no control signal, even if it is determined to be within the range at the timing when the control signal is transmitted, it is determined to be out of the range during the period when the control signal is not transmitted.

In order to solve the above-mentioned problems, the present invention determines the received electric field strength during a waiting period when a mobile radio station receives a control channel, and a frame synchronization signal constituting a control signal received from a radio base station. Multi-channel access, the RSSI voltage is sampled during the period from the end of the detection of the frame synchronization signal to the end of the control signal, so as to obtain an appropriate reception electric field strength for in-range determination. It is an object of the present invention to provide a received electric field strength detection method in a wireless system.

[0010]

In order to achieve the above object, a method for detecting a received electric field strength in a multi-channel access radio system according to the present invention is a radio base station for controlling and controlling a communication line, and a radio base station for the radio base station. In a radio system of a multi-channel access system configured with a mobile radio station that performs communication according to control and control, a control signal and a carrier that form a frame synchronization signal as a part of the configuration are transmitted from the radio base station to the mobile radio station. Send on control channel,
When the mobile radio station receives and detects the control signal and the carrier, and if the frame synchronization of the control signal is detected, the strength of the received electric field is detected by the carrier level in the signal period following the frame synchronization signal of the control signal. It is a thing.

More specifically, the received electric field strength detecting method in the multi-channel access radio system of the present invention comprises a received electric field strength detecting circuit for direct-current detecting a carrier level of a carrier received by a mobile radio station from a radio base station, A receiver including a voltage conversion circuit that converts a detection output input from the received electric field intensity detection circuit into a voltage, an A / D converter that converts the output voltage input from the reception unit into digital data, and the A / D A central processing unit for comparing digital data input from the converter with a preset reference value, and if a frame synchronization signal of the control signal received from the radio base station is detected, a signal following the control signal. During the period, A / D conversion of the A / D converter is performed, and digital data is previously stored in the central processing unit. Performs comparison between the constant reference value, the comparison result is to hold up the processing of the next control signal is terminated.

The operation of the present invention will be described. A method of detecting a received electric field strength in a multi-channel access radio system according to the present invention comprises a radio base station for controlling and controlling a communication line and communication according to the control and control of the radio base station. In a wireless system of a multi-channel access method configured with a mobile radio station, a control signal and a carrier, which form a frame synchronization signal as a part of the configuration, are transmitted from the radio base station to the mobile radio station on a control channel. , Receiving and detecting a control signal and a carrier in the mobile radio station,
If the frame synchronization of the control signal is detected, the strength of the received electric field is detected by the carrier level in the signal period following the frame synchronization signal of the control signal.The carrier from the radio base station on the control channel can be continuously transmitted. Instead, it is transmitted intermittently at a fixed cycle, and in-range judgment by receiving electric field strength detection while waiting on the control channel performed by the mobile radio station judges only the period during which the control signal is received and transmits the control signal. The electric field detection during the period not performed is ignored.

[0013]

1 and 4 show an embodiment of a method for detecting a received electric field strength of an MCA radio system according to the present invention.
This will be described using. FIG. 1 is a diagram showing a timing of a control signal transmitted from a radio base station in an MCA radio system of the present invention and a timing of a received electric field strength detection operation in a mobile radio station according to the present invention, and FIG. 4 is a mobile radio. It is a schematic block diagram of the receiver of a station. The configuration of the mobile radio station is the same as that of the conventional technique. In FIG. 1, reference numeral 1 is a control signal transmission carrier transmitted from a radio base station, and 2 is a control signal transmitted by modulating the control signal transmission carrier 1. In the MCA radio system of the present invention, the radio base station constantly transmits the control signal 2 in the control channel at a constant cycle, and the control signal transmission carrier 1 transmitted from the radio base station is synchronized with the control signal 2. It is sent intermittently. On the other hand, the mobile radio station receives the control signal 2 together with the control signal transmission carrier 1 transmitted from the radio base station while waiting for reception on the control channel. At this time, the mobile radio station has obtained the reception demodulation output signal demodulated in the reception unit 10 (see FIG. 4),
This reception demodulation output signal is input to the control signal detection unit 13,
The reception control signal is demodulated, this reception control signal is output to the central processing unit 12, and the central processing unit 12 analyzes the reception control signal.

On the other hand, the control signal receiving carrier 3 is obtained by the receiving section 10, and the control signal receiving carrier 3 is detected by the reception electric field strength detection circuit (not shown) of the receiving section 10 and the detection output is obtained. A voltage conversion circuit (not shown) generates an RSSI voltage 4 converted into a DC detection voltage, and A
It is output to the / D converter 11. Here, the control signal 2 will be described in more detail. As shown in FIG. 1, the control signal 2 includes a bit synchronization signal 6 and a frame synchronization signal 7.
And a data signal 8. In the mobile radio station shown in FIG. 4, the reception control signal input to the central processing unit 12 is analyzed by the central processing unit 12, and the frame synchronization signal 7 forming the reception control signal is the self station (mobile radio station).
The signal of the MCA radio system to which the A.D. belongs to, the A / D converter 11 samples the input RSSI voltage 4 in the period from the end of the frame synchronization signal 7 to the end of the data signal 8. A / D
The sampling output data output from the converter 11 is input to the central processing unit 12 and compared with preset reference data.

The reference data preset in the central processing unit 12 is set to a sampling data value corresponding to the limit reception signal level (for example, reception reference sensitivity level) of the reception electric field strength that can sufficiently secure the communication quality. By comparing the sampling output data with the reference data in the central processing unit 12, if the sampling output data is larger than the reference data and the reception signal level is larger than the limit value of the reception electric field strength that can sufficiently secure the communication quality, To determine. This determination result is held until the next control signal reception detection.

As a means for determining whether or not the mobile radio station in the MCA radio system is in the system coverage area while waiting for the control channel reception, when the decision is made by the measured value of the received electric field strength, in the conventional method, the mobile radio station is always Since the reception electric field strength of the own station is monitored and the RSSI voltage is sampled at a constant cycle, the reception electric field strength during the period when the control signal is not transmitted from the radio base station is also measured. Although the reception electric field strength could not be obtained, in the present invention, the control signal transmitted by the radio base station and the control signal transmission carrier in the control channel are constantly output in a constant cycle, and the control transmitted from the radio base station is performed. By making the determination only during the signal transmission period, it is possible to make an accurate determination of the area.

[0017]

According to the present invention, the mobile radio station receives the control channel and determines the received electric field strength during the waiting period if the frame synchronization signal constituting the control signal received from the radio base station is detected. For example, in the period from the end of detection of the frame synchronization signal to the end of the control signal, RS
It is possible to provide a method for detecting a received electric field strength of an MCA wireless system, which is configured to sample an SI voltage and obtain an appropriate received electric field strength for making an area judgment. In the above-described embodiment, the method of sampling the RSSI signal by the A / D converter at the time when the detection of the frame synchronization signal is completed and detecting the electric field strength only during the control signal period has been described. The sampling operation in the D converter is always performed, and when the detection of the frame synchronization signal is completed, the comparison processing of the sampling data signal in the central processing unit may be started.

[Brief description of drawings]

FIG. 1 is a diagram showing transmission timings of control signals and carriers in a radio base station according to the present invention, reception carriers and reception electric field strength detection voltages in mobile radio stations, and sampling timings.

FIG. 2 is a diagram illustrating an example of a line connection procedure between a radio base station and a mobile radio station of a control channel in the MCA system.

FIG. 3 is a diagram showing a transmission timing of a control signal and a carrier in a conventional radio base station, a reception carrier and a reception electric field strength detection voltage in a mobile radio station, and a sampling timing.

FIG. 4 is a schematic block diagram of a receiving device of a mobile radio station.

[Explanation of symbols]

10 ... Receiving part, 11 ... A / D converter, 12 ... Central processing unit, 13 ... Control signal detecting part. 1, 21 ... Control signal transmission carrier, 2, 22 ... Control signal, 3, 23 ... Control signal reception carrier, 4, 24 ... Reception electric field strength detection voltage, 5,
25 ... Sampling signal, 6 ... Bit synchronization signal, 7 ... Frame synchronization signal, 8 ... Data signal,

Claims (2)

[Claims] 1. A wireless system of a multi-channel access system comprising a wireless base station which controls and controls a communication line and a mobile wireless station which performs communication according to the control and control of the wireless base station. To the mobile radio station, a control signal having a frame synchronization signal as a part of the configuration and a carrier are transmitted on a control channel, and the mobile radio station receives and detects the control signal and the carrier, A method for detecting a received electric field strength in a multi-channel access wireless system, wherein the strength of a received electric field is detected by a carrier level of a signal period following a frame synchronous signal of a control signal if frame synchronization is detected. 2. The mobile radio station according to claim 1, wherein the mobile radio station detects the electric field strength of the carrier received from the radio base station by direct current detection, and a detection output inputted from the reception electric field strength detection circuit. To a voltage, a receiving unit including a voltage converting circuit, an A / D converter that converts an output voltage input from the receiving unit into digital data, and digital data input from the A / D converter. A central processing unit for comparing with a reference value, and when a frame synchronization signal of the control signal received from the radio base station is detected, during the signal period following the control signal, the A / D converter The A / D conversion is performed, the central processing unit compares the digital data with a preset reference value, and the comparison result is controlled by the next control. Received signal strength detecting method in a multi-channel access radio system, characterized in that the holding until processing is completed for Nos.