JPH07264659A - Radio telephone equipment - Google Patents

Abstract

PURPOSE:To provide the radio telephone equipment which has high reliability by performing optimum control over the transmission timing of a control carrier that a radio base station sends and improving the connectivity with a mobile station as to the TDMA/TDD system radio telephone equipment. CONSTITUTION:When plural radio base stations 12-14 are contiguous, control carriers that the respective base stations 12-14 send are asynchronous and possibly interfere with or disturb one another, so when the radio base stations are powered ON, the electric field intensity levels of control carriers that other contiguous radio base stations send, are measured for a certain time before control carriers are sent to generate a control carrier presence/absence data table; and when no radio base station sends a carrier is retrieved by using the table and the control carrier of the station is sent out at the retrieved timing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TDMA / TDD system radiotelephone device which is used for private use or public use.

[0002]

2. Description of the Related Art FIG. 9 shows a system configuration of a conventional wireless telephone device of this type. In FIG. 9, 91 is a public line network, 92, 93 and 94 are radio base stations, and 95, 96 and 9
Reference numeral 7 is a mobile station belonging to each of the radio base stations 92, 93 and 94. Reference numerals 98 and 99 are a first control carrier and a second control carrier used in this system, respectively.

Conventionally, in this type of radio base station, carrier sense is not required prior to the transmission of the control carrier, so that the timing of transmitting the control carrier is asynchronous in a plurality of radio base stations, and adjacent radio base stations are adjacent to each other. In the wireless base station, the control carriers may interfere with each other. In order to reduce these interferences, two waves of the first control carrier 98 and the second control carrier 99 are used to reduce the probability of mutual control carrier interference. In the example shown in FIG. 9, the second control carrier 99 of the radio base station 92 is at a timing of causing mutual interference with the first control carrier 98 of the radio base station 93. As a result, the radio base station 92 is The first control carrier 98 and the radio base station 93 are the second control carrier 99,
The radio base station 94 does not interfere with the control carriers of the other radio base stations by the first and second control carriers 98 and 99, and can be connected to the mobile stations 95, 96 and 97 without any problem. Is possible.

[0004]

However, in the above-mentioned conventional radiotelephone device, when the number of adjacent radio base stations increases, the probability of interference of the control carrier increases,
There are problems that the connection between the own station and the mobile station is deteriorated or that the control carrier of another base station is disturbed.

The present invention solves such a conventional problem, and provides a highly reliable radiotelephone device capable of preventing interference of a control carrier and favorably connecting to a mobile station. The purpose is to

[0006]

In order to achieve the above object, the present invention provides a means for measuring the electric field strength of a control carrier for a certain period of time, and a control carrier transmitted by another adjacent radio base station. And a means for transmitting the control carrier of its own station while avoiding the transmission timing.

[0007]

Therefore, according to the present invention, the radio base station can detect the weak electric field strength of the control carrier by measuring and learning the electric field strength distribution of the control carrier for a certain period of time. By transmitting the control carrier from the radio base station, it is possible to satisfactorily establish connection with the mobile station of its own station, and reduce interference with other radio base stations due to mutual interference of the control carriers. .

[0008]

【Example】

Example 1 An example of the present invention will be described below.
FIG. 1 shows a system configuration of a wireless telephone device according to a first embodiment of the present invention. In FIG. 1, 11 is a public line network, 12, 13, and 14 are radio base stations, and 15 and 1.
Mobile stations 6 and 17 belong to the radio zones of the radio base stations 12, 13 and 14, respectively. (A) is a radio base station 12
Control carrier transmission timing, (b) control carrier transmission timing of the radio base station 13, (c) control carrier distribution in the radio base station 14, (d) radio base station 1
4 is the control carrier transmission timing of No. 4.

Next, the operation of the first embodiment will be described. The radio base stations 12 and 13 are already in the public line network 1.
It is assumed that the control carrier is connected to No. 1 and the operation is started, and the control carrier is transmitted at the respective transmission timings (a) and (b). The radio base station 14 adjacent to the radio base stations 12 and 13 measures the electric field strengths of the control carriers of these radio base stations 12 and 13 to obtain the control carriers transmitted from the radio base stations 12 and 13. Since the control carrier of the own station is transmitted aiming at a vacant timing during that time, the connection with the mobile station 17 of the own station can be satisfactorily performed, and the other radio base stations 12, 1
It is possible to prevent mutual interference with the third control carrier.

FIG. 2 shows the radio base stations 12, 13, 14 described above.
2 shows the configuration of a portion for measuring the received electric field of the. In FIG. 2, 21 is an antenna, 22 is a wireless transmission / reception unit, 23 is an electric field intensity measuring unit, 24 is a CPU, 25 is a timing control unit, 26 is a RAM, and 27 is a ROM. Antenna 21
And the control carrier received by the wireless transmission / reception unit 22 is
The electric field strength measuring unit 23 measures the strength of the received electric field, converts it into 8-bit digital data, and outputs it. CPU
The 24 reads out the 8-bit digital data as one point and analyzes it to determine the presence or absence of a control carrier at that time. In the data table, "0" (without carrier) or "1" (with carrier) Assign information,
It is stored in the RAM 23 based on the time axis. After measurement, CP
The U 24 searches for a vacant timing of the control carrier based on the data stored in the RAM 23, and notifies the timing control unit 25 of the timing. The timing control unit 25 instructs the wireless transmission / reception unit 22 to transmit the control carrier at the notified timing. RO
Such a control program is stored in M27, and the CPU 24 operates in accordance with this program.

Next, the electric field strength measuring process in this embodiment will be described with reference to FIG. In FIG. 3, after the power is turned on in step 31, the peripheral I / O is set in step 32.
Is initialized, and the reception frequency is set to the control carrier in step 33. In step 34, the CPU 24 reads out a total of 5000 points of data from the electric field intensity measuring unit 23 at intervals of 200 μs for 1 second. Next, in step 35, 5000
Create a data table based on the time axis of the point measurement results. Then, in step 36, the empty timing of the electric field is detected by searching the data table, and in step 37, the timing controller 25 is notified of the transmission timing. Then, in step 38, the control carrier is transmitted in the same manner as the conventional one.

Next, the electric field strength table will be described with reference to FIG. In FIG. 4, 41 is a control carrier distribution in the radio base station 14, and 42 is a data table as a result of measuring the electric field strengths of these control carriers. Here, "0" means that there is no carrier, and "1" means that there is a carrier. If there is a carrier for control, CPU
In 24, the electric field strength of 5000 points in total is measured at intervals of 200 μs for 1 second, weighted by the electric field strength level for each point, and patterned with “0” and “1”. This table corresponds to the time axis, and it is possible to detect the vacancy of the control carrier by searching the pattern of "0".

(Second Embodiment) Next, a second embodiment of the present invention will be described. This embodiment is the same as the first embodiment in the configuration and the main operation, but the method of creating and retrieving the electric field strength measurement data table is different from that of the first embodiment. FIG. 5 shows a data table of electric field strength in this embodiment. In FIG. 5, 51 is a control carrier distribution in a certain radio base station, and 52 is a data table of the measurement results of the electric field strengths of these control carriers. Here, “0” means no control carrier,
“1” means that there is a control carrier (medium), and “2” means that there is a control carrier (strong). When analyzing the 8-bit data read from the electric field strength measurement unit 22, the CPU 24 does not simply determine the presence or absence of a carrier, but
A table is created by dividing the level of electric field strength into three levels. After that, when searching for the timing when the control carrier is available, the search starts from "0", which has a low level,
If the data is only "0" and the timing cannot be detected, the next level "1" is searched. In this way, by finely controlling the level difference of the electric field strength,
It is possible to detect a more optimal transmission timing of the control carrier. It should be noted that the number of electric field strength levels is not limited to three, and can be set to an optimum number depending on the device.

(Embodiment 3) Next, a third embodiment of the present invention will be described. FIG. 6 shows the system configuration of the wireless telephone device in this embodiment. In FIG. 6, 61,
62 is a main device connected to the public line network, 63 and 64 are radio base stations connected to the main device 61 by a line, 65 and 66 are radio base stations connected to the main device 62 by a line, 67 and 6
8, 69 and 70 are radio base stations 63, 64 and 6 respectively.
These mobile stations belong to the wireless zones of 5, 66. (A) is a control carrier transmission timing of the wireless base station 63,
(B) is a control carrier transmission timing of the radio base station 64, (c) is a control carrier distribution in the radio base station 65,
(D) is a control carrier transmission timing of the radio base station 65, (e) is a control carrier distribution in the radio base station 66,
(F) is a control carrier transmission timing of the radio base station 66.

Next, the operation of the third embodiment will be described. The main operation of each of the radio base stations 64-66 is the same as that of the first embodiment, and the difference is that the data table of the electric field strength measurement created by the plurality of radio base stations connected to one main device is This is to once collect the data in the main device and manage the transmission timing of the control carrier of each radio base station on the main device side.

In FIG. 6, main device 61 and main device 62
Operate asynchronously, and the wireless base stations 63 and 64 connected to the main device 61 operate synchronously. Similarly, the radio base stations 65 and 66 operate in synchronization. Here, the radio base station 6 is within the range where the radio waves of the radio base station 63 reach.
5 is included, and the radio base station 66 is included in the range where the radio wave of the radio base station 64 reaches. Radio base station 65 at this time
The distribution of the control carriers received by the wireless base station 66 is as shown in (c), and the distribution of the control carriers received by the wireless base station 66 is as shown in (e). When the system of the main device 62 is started up, the radio base stations 65 and 66 respectively measure the electric field strengths of the control carriers, and based on the measured electric field strengths, a data table is created in the same manner as in the first embodiment. Next, the data tables of the wireless base stations 65 and 66 are set to the main device 6
2, the main device 62 processes the plurality of collected data tables, searches for a vacant timing of the control carrier, and notifies the radio base stations 65 and 66 of the results. As a result, the timings of the control carriers transmitted by the radio base stations 65 and 66 are (d) and (f), and the main device 62 centrally manages the vacant timing to allow the radio base stations to communicate with other radio base stations. The control carrier can be efficiently transmitted without mutual interference.

FIG. 7 shows the configurations of the main device 61 and the radio base stations 63 and 64 in this embodiment, and the configurations of the other main device 62 and the radio base stations 65 and 66 are the same.
In the main device 61, 71 is a CPU, 72 is a ROM, 7
3 is a RAM, 74 is a timing controller, 75 is a line interface, and 76 is a line connecting the main unit 61 and the radio base station 63. In the wireless base station 63, 77 is a line interface, 78 is a CPU, 79 is a ROM, 8
Reference numeral 0 is a RAM, 81 is a timing control unit, 82 is an electric field strength measurement unit, 83 is a wireless transmission / reception unit, and 84 is an antenna.

In FIG. 7, the operation of each radio base station 63, 64 is the same as that of the first embodiment, and the created data table is notified to the main unit 61 via the line interface 77 and line 76. In the main device 61, the CPU 71 creates a new data table in the RAM 73 via the line interface 75 based on the data tables from the wireless base stations 63 and 64. After that, the data table is searched to detect the vacant timing of the electric field, and the timing control unit 74 is notified, and the timing control unit 74 notifies the transmission timing of each radio base station 63, 64. These programs are stored in the ROM 72. In each of the wireless base stations 63 and 64, the CPU 78 notifies the timing control unit 81 of the transmission timing in accordance with the timing notified from the main device 61, and the timing control unit 81 notifies the wireless transmission / reception unit 83 of the control carrier at that timing. Instruct to send.

FIG. 8 shows a data table of electric field strength in this embodiment. In FIG. 8, (a) is a control carrier distribution in the radio base station 65, (b) is a control carrier distribution in the radio base station 66, 85 is a data table of electric field strength created in the radio base station 65, and 86 is a radio wave. Data table of electric field strength created by the base station 66, 8
Reference numeral 7 is a data table created by the main unit 62 by taking the logical sum of these two electric field intensity data tables.

The main unit 62 includes radio base stations 65 and 66.
When the data table of the electric field strength is notified from the data table, the data table indicating the presence or absence of the control carrier corresponding to one time axis is obtained by taking the logical OR of the data for each of the two data tables. Can be created. As a result, in the radio telephone device including the main device, it is possible to control the transmission timing of the control carrier and prevent mutual interference with other main devices.

(Fourth Embodiment) The fourth embodiment of the present invention is realized by combining the first, second and third embodiments. As a result, a more optimal transmission timing of the control carrier can be realized in the wireless telephone device including the main device.

[0022]

As is apparent from the above embodiment, the present invention provides means for measuring the electric field strength of the control carrier for a certain period of time and the transmission timing of the control carrier transmitted by another adjacent radio base station. And the means for transmitting the control carrier of its own station while avoiding the transmission timing, and the radio base station measures the electric field strength distribution of the control carrier for a certain period of time, It is possible to detect a weak electric field strength, and the wireless base station transmits a control carrier at that timing, so that it is possible to satisfactorily establish a connection with its own mobile station,
It is possible to reduce interference with other radio base stations due to mutual interference between control carriers.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration of a wireless telephone device according to a first embodiment of the present invention and a timing diagram showing transmission timing in each wireless base station.

FIG. 2 is a block diagram showing a configuration of each wireless base station according to the first embodiment of the present invention.

FIG. 3 is a flowchart for measuring electric field strength in the first embodiment of the present invention.

FIG. 4 is a schematic diagram of an electric field intensity distribution and its data table in the first embodiment of the present invention.

FIG. 5 is a schematic diagram of an electric field intensity distribution and its data table in the second embodiment of the present invention.

FIG. 6 is a block diagram showing a system configuration of a wireless telephone device according to a third embodiment of the present invention and a timing diagram showing transmission timing in each wireless base station.

FIG. 7 is a block diagram showing configurations of a main device and a radio base station according to a third embodiment of the present invention.

FIG. 8 is a schematic diagram of an electric field strength distribution and its data table in the third embodiment of the present invention.

FIG. 9 is a block diagram showing a system configuration of a wireless telephone device in a conventional example and a timing diagram showing a transmission timing of each wireless base station.

[Explanation of symbols]

 11 public line network 12, 13, 14 wireless base station 15, 16, 17 mobile station 21 antenna 22 wireless transmitter / receiver unit 23 electric field strength measuring unit 24 CPU 25 timing control unit 26 RAM 27 ROM

Claims (3)

[Claims] 1. A radio base station and a mobile station are provided, and a means for measuring the electric field strength of a control carrier for a certain period of time and a transmission timing of a control carrier transmitted by another adjacent radio base station are searched. , A means for transmitting the control carrier of its own station while avoiding the transmission timing thereof. 2. The radio according to claim 1, wherein a vacant timing of the control carrier is detected by creating a data table in which the measurement result of the electric field strength of the control carrier is weighted by the electric field strength level and searching the data table. Telephone device. 3. The radiotelephone device according to claim 1, further comprising a main device in which a plurality of radio base stations are connected by a line, and the transmission timing of a control carrier of each radio base station is managed by the main device.