JP2001358615A - Frequency-hopping communication system and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a deterioration of a communication quality by suitably changing a frequency hopping sequence, when there is a slot using a hopping frequency of a deteriorated reception state. SOLUTION: In a frequency-hopping communication system for communicating between a base station and a mobile station, while frequency hopping based on a prescribed frequency-hopping sequence, the mobile station has an interference wave level detector 6 for detecting an interference wave level of each frequency at each frequency hopping period, and a controller 9 for controlling, to change the present frequency hopping sequence to another frequency hopping sequence. This change is conducted, by selecting the frequency hopping sequence having a small frequency-hopping sequence number, the lowest interference wave level from a past history and a large correlation, as well as being one which is not being used by another mobile station.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system using a spread spectrum communication system, and more particularly, to a frequency for performing communication between a base station and a mobile station while performing frequency hopping based on a predetermined frequency hopping sequence. The present invention relates to a hopping communication system.

[0002]

2. Description of the Related Art Conventionally, a frequency hopping communication system has been known as one of spread spectrum communication systems. FIG. 8 is a diagram showing an overall outline of a conventional frequency hopping communication system. In FIG. 8, a mobile station 110 communicates with a fixedly installed base station 120 using a frequency hopping communication method. The radio cell 30 is connected to the base station 1
20 indicates a range in which data transmission / reception is performed between the base station 120 and the mobile station 110. The frequency hopping communication system shown in FIG. 8 has a configuration of seven cell repetitions, and the entire service area can be covered by seven frequency groups. The shaded area shown in FIG. 8 is a repetition area, and the number of cells serving as a unit of repetition is called the number of repetition cells.

[0003] All mobile stations 110 and each base station 120 in the repetition area are managed by a central control station (not shown) connected to each base station 120, and this central control station transmits a preset frequency hopping sequence to each base station. Base station 12
Specify 0. Each base station 120 having received this designation designates a frequency for the mobile station 110 and performs frequency hopping at a fixed hopping cycle. This makes it possible to distribute the same frequency interference power to all mobile stations 110 in the repetition area.

FIG. 9 shows hopping sequences C1 to C6 when frequencies f1, f2 and f3 are designated for one radio cell 30. For example, cell "A" in FIG.
When the frequencies f1 to f3 are specified for the cell "B" and the same frequencies f1 to f3 are specified for the cell "B", the three mobile stations m1 to m3 in the cell "A" respectively receive
Is used to perform frequency hopping. The three mobile stations m4 to m6 in the cell “B” perform frequency hopping using the hopping sequences C4 to C6, respectively.

[0005] FIG. 10 shows mobile stations m1 to m1 in cell "A".
It is a timing chart which shows the frequency hopping state of m3. The mobile station m1 uses the frequencies f1, f2, and f3 when outputting the slots S1 to S3, and the mobile station m2 uses the frequencies f2, f3, and f1 when outputting the slots S1 to S3. m3 is the frequency f3, f3 when outputting slots S1 to S3, respectively.
2, f2 is used. In the slots S1 to S3, data obtained by dividing original data such as audio and adding a header and the like are arranged. As a result, the mobile stations m1 to m3 in the cell “A” are not assigned the same frequency at the same time.

On the other hand, hopping sequences C4 to C6 are similarly assigned to the mobile stations m4 to m6 of the cell "B". As a result, mobile stations m1 to m1 in cell "A"
The same frequency interference power received by m3 by the mobile stations m4 to m6 in the cell “B” is once every three slots.

[0007] In this way, a mobile station that is strongly affected by interference can reduce the required desired signal to co-frequency interference power ratio by the frequency diversity effect.
Such a frequency hopping communication system is described in, for example, a mobile communication system disclosed in JP-A-5-110499 or a spread spectrum communication method disclosed in JP-A-6-334630.

FIG. 11 is a block diagram showing a configuration of a mobile station in a conventional frequency hopping communication system. FIG.
, The received signal 3r is a downlink signal received from the base station 120, and is input to the receiving unit 3 via the antenna 1 and the switching unit SW. The receiving unit 3 receives the received signal 3r based on the received frequency data 5r from the synthesizer 5.
And outputs the reception slot data 4r to the transmission / reception data processing unit 4. The transmission / reception data processing unit 4 decomposes the reception slot data 4r and outputs the reception data 4o. Further, the transmission / reception data processing unit 4 extracts the frequency hopping sequence data 9r from the reception slot data 4r. Further, the transmission / reception data processing unit 4 outputs a timing signal 4g to the synthesizer unit 5.

On the other hand, the transmission data 4i is input to the transmission / reception data processing unit 4, and the transmission / reception data processing unit 4 generates transmission slot data 4t and outputs it to the transmission unit 2. The frequency hopping sequence data 9r output from the transmission / reception data processing unit 4 is input to the control unit 9. The control unit 9 determines a frequency hopping sequence and a hopping frequency to hop based on the input frequency hopping sequence data 9r. Then, the control unit 9 notifies the synthesizer unit 5 of the determined hopping frequency as frequency data 9t.

The synthesizer unit 5 generates transmission frequency data 5t in order to switch and generate a hopping frequency based on the input frequency data 9t and the timing signal 4g.
To the transmission unit 2 or the reception frequency data 5r to the reception unit 3.

The transmission slot data 4t output from the transmission / reception data processing unit 4 is output to the transmission unit 2,
Modulates the input transmission slot data 4t with the transmission frequency data 5t and switches the transmission signal 2t to the switching unit SW.
And output to the base station 120 via the antenna 1. The switching unit SW is switched between transmission and reception by the control unit 9.

[0012]

However, the above-described frequency hopping communication system always uses the frequency hopping sequence specified in the initial setting until the end of communication, regardless of the reception state of the mobile station 110. Therefore, when there is a slot using the hopping frequency whose reception state has deteriorated, there is a problem that the reception state deteriorates in each frequency hopping cycle.

The present invention has been made in view of the above,
It is an object of the present invention to obtain a frequency hopping communication system and a method thereof that can appropriately change a frequency hopping sequence when there is a slot using a hopping frequency whose reception state has deteriorated and can prevent communication quality from deteriorating.

[0014]

In order to achieve the above object, a frequency hopping communication system according to the present invention performs communication between a base station and a mobile station while performing frequency hopping based on a predetermined frequency hopping sequence. In the performing frequency hopping communication system, the mobile station,
Detecting means for detecting an interference wave level of each frequency for each frequency hopping cycle, and control for changing the current frequency hopping sequence to another frequency hopping sequence when the interference wave level detected by the detecting means exceeds a predetermined value And control means for performing the following.

According to the present invention, the mobile station detecting means comprises:
The interference wave level of each frequency is detected for each frequency hopping cycle, and the control unit changes the current frequency hopping sequence to another frequency hopping sequence when the interference wave level detected by the detection unit exceeds a predetermined value. Control is performed.

[0016] A frequency hopping communication system according to the next invention is a frequency hopping communication system for performing communication between a base station and a mobile station while performing frequency hopping based on a predetermined frequency hopping sequence. The base station includes a detecting unit that detects an interference wave level of each frequency for each frequency hopping cycle, and when the interference wave level detected by the detecting unit exceeds a predetermined value, the base station changes the current frequency hopping sequence to another frequency. Control means for performing control for changing to a hopping sequence is provided.

According to the present invention, the detecting means of the mobile station comprises:
The interference wave level of each frequency is detected for each frequency hopping cycle, and the control unit of the base station replaces the current frequency hopping sequence with another frequency hopping sequence when the interference wave level detected by the detection unit exceeds a predetermined value. Control to change to.

[0018] In the frequency hopping communication system according to the next invention, in the above invention, the control unit is currently used by another mobile station when the interference wave level detected by the detection unit exceeds a predetermined value. The frequency hopping sequence having no frequency hopping sequence and having a pre-assigned frequency hopping sequence number is controlled to change the value of the frequency hopping sequence number to the smallest frequency hopping sequence. .

According to the present invention, when the interference wave level detected by the detection means exceeds a predetermined value, the control means is a frequency hopping sequence not currently used by another mobile station, and Control is performed such that the value of the frequency hopping sequence number is changed to the minimum frequency hopping sequence from the frequency hopping sequence group having the allocated frequency hopping sequence number.

[0020] In the frequency hopping communication system according to the next invention, in the above invention, the base station retains a history of past interference wave levels for each frequency hopping sequence of a preset frequency hopping sequence group. The control unit further includes, when the interference wave level detected by the detection unit exceeds a predetermined value, refers to the history of the interference wave level, and sets the current frequency hopping sequence to another mobile station. The frequency hopping sequence that is not used is controlled to be changed to a frequency hopping sequence having the minimum interference wave level from the group of frequency hopping sequences.

According to the present invention, when the interference wave level detected by the detection means exceeds a predetermined value, the control means refers to the history of the interference wave level, and determines the current frequency hopping sequence by the other. Is a frequency hopping sequence that is not currently used by the mobile station and the control is performed to change the frequency hopping sequence from the group of frequency hopping sequences to the frequency hopping sequence with the minimum interference wave level.

[0022] In the frequency hopping communication system according to the next invention, in the above invention, the control means, when the interference wave level detected by the detection means exceeds a predetermined value, converts the current frequency hopping sequence into another signal. The mobile station is not currently using the frequency hopping sequence, and, from among a group of preset frequency hopping sequences, the correlation value with the current frequency hopping sequence is characterized by performing control to change to the minimum frequency hopping sequence. I do.

According to the present invention, when the interference wave level detected by the detection means exceeds a predetermined value, the control means converts the current frequency hopping sequence to a frequency hopping sequence not currently used by another mobile station. In addition, control is performed to change the frequency hopping sequence from the preset frequency hopping sequence group to the frequency hopping sequence having the minimum correlation value with the current frequency hopping sequence.

[0024] A frequency hopping communication method according to the next invention is a frequency hopping communication method for performing communication between a base station and a mobile station while performing frequency hopping based on a predetermined frequency hopping sequence.
A detection step of detecting an interference wave level of each frequency for each frequency hopping cycle, and a change of changing the current frequency hopping sequence to another frequency hopping sequence when the interference wave level detected by the detection step exceeds a predetermined value. And a step.

According to the present invention, the mobile station detects the interference wave level of each frequency in each frequency hopping cycle in the detection step, and the change level changes the interference wave level detected in the detection step to a predetermined value. If exceeded,
The current frequency hopping sequence is changed to another frequency hopping sequence.

A frequency hopping communication method according to the next invention is a frequency hopping communication method for performing communication between a base station and a mobile station while performing frequency hopping based on a predetermined frequency hopping sequence. A detecting step of detecting an interference wave level of each frequency for each hopping cycle; and, if the interference wave level detected by the detection means exceeds a predetermined value, the base station changes the current frequency hopping sequence to another frequency hopping. And a changing step of changing to a series.

According to the present invention, in the detecting step, the mobile station detects an interference wave level of each frequency in each frequency hopping cycle, and in the changing step, the base station detects the interference wave level detected by the detecting means. When the level exceeds a predetermined value, the current frequency hopping sequence is changed to another frequency hopping sequence.

[0028] In the frequency hopping communication method according to the next invention, in the above-mentioned invention, the changing step is performed by another mobile station when the interference wave level detected by the detection means exceeds a predetermined value. A frequency hopping sequence having no frequency hopping sequence and having a frequency hopping sequence number assigned in advance is changed to a frequency hopping sequence having the smallest value of the frequency hopping sequence number.

According to this invention, when the interference wave level detected in the detecting step exceeds a predetermined value, the changing step is a frequency hopping sequence not currently used by another mobile station, and The value of the frequency hopping sequence number is changed from the frequency hopping sequence group having the assigned frequency hopping sequence number to the minimum frequency hopping sequence.

[0030] In the frequency hopping communication method according to the next invention, in the above invention, the base station retains a history of past interference wave levels for each frequency hopping sequence of a preset frequency hopping sequence group. The method further includes the step of: when the interference wave level detected by the detection step exceeds a predetermined value, the change step refers to the history of the interference wave level, the current frequency hopping sequence, the other mobile station A frequency hopping sequence that is not currently used and is changed to a frequency hopping sequence having the minimum interference wave level from the group of frequency hopping sequences.

According to the present invention, in the history holding step, the base station holds the history of the past interference wave level for each frequency hopping sequence of the preset frequency hopping sequence group, and in the changing step, If the interference wave level detected by the detection step exceeds a predetermined value, refer to the history of the interference wave level, the current frequency hopping sequence, a frequency hopping sequence that is not currently used by other mobile stations, Further, the frequency hopping sequence is changed to the frequency hopping sequence having the minimum interference wave level from the frequency hopping sequence group.

[0032] In the frequency hopping communication method according to the next invention, in the above invention, in the changing step, when the interference wave level detected by the detection step exceeds a predetermined value, the current frequency hopping sequence is replaced with another signal. The mobile station is characterized by changing to a frequency hopping sequence that is not currently used by the mobile station and that has a minimum correlation value with the current frequency hopping sequence from a preset frequency hopping sequence group.

According to the present invention, when the interference wave level detected by the detection step exceeds a predetermined value by the change step, the current frequency hopping sequence is replaced with a frequency hopping sequence not currently used by another mobile station. In addition, the correlation value with the current frequency hopping sequence is changed from the preset frequency hopping sequence group to the frequency hopping sequence having the minimum value.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a frequency hopping communication system and a method thereof according to the present invention will be described below in detail with reference to the accompanying drawings.

Embodiment 1 FIG. 1 is a diagram showing an outline of a frequency hopping communication system according to a first embodiment of the present invention, and corresponds to the frequency hopping communication system shown in FIG. However, the configuration of the mobile station 10 corresponding to the mobile station 110 or the configuration of the base station 20 corresponding to the base station 120 is different.

In FIG. 1, each radio cell 30 indicates a range in which data is transmitted and received between the base station 20 and the mobile station 10 with the corresponding base station 20 as the center. Mobile station 10
If the interference wave level measured for each frequency hopping cycle exceeds a predetermined level, the currently used frequency hopping sequence is changed.If the interference wave level does not exceed the predetermined level, the currently used frequency hopping sequence is changed. Do not change That is, in the first embodiment, the mobile station measures the interference wave level for each frequency hopping cycle, and determines whether or not to change the currently used frequency hopping sequence based on the interference wave level. ing.

Here, cells "A" and "B" are:
Frequency hopping sequences Z1 to Z7 given to cells "A" and "B" when four hopping frequencies F1, F2, F3 and F4 are given will be described. It is assumed that mobile station M1 and M2 exist in cell "A", and mobile station M3 exists in cell "B".

In FIG. 2, the frequency hopping sequence Z1
To Z3 are assigned to the mobile stations M1 to M3, respectively. Note that specific frequency hopping sequences Z1 to Z4
Are “F1 → F2 → F3 → F4” and “F2 →
F3 → F4 → F1 ”,“ F3 → F1 → F2 → F4 ”,
“F4 → F2 → F1 → F3”. Each mobile station M1-M
No. 3 repeatedly uses the assigned frequency hopping sequences Z1 to Z3 unless a change instruction is given. The time during which one frequency hopping sequence is used is called a frequency hopping cycle.

Here, the data output from the base station 20 of the cell "B" is received by each of the mobile stations M1 to M3 at the timing of the slot S4, and the data output from the base station 20 of the cell "A". Is received by the mobile stations M1 to M3 at the timing of the slot S4, the frequency F4 used by the mobile station M1 of the cell “A” is used by the mobile station M3 of the cell “B”. Since the frequency is the same as the frequency F4, the mobile station M1 may receive a strong interference wave from the base station 20 of the cell “B”. When the interference wave level in the slot S4 exceeds a predetermined value, the mobile station M1 changes the currently used frequency hopping sequence Z1 to a frequency hopping sequence Z4.

On the other hand, the frequency hopping sequence Z2 used by the mobile station M2 includes the frequencies F1 to F4 used at the timings of the slots S1 to S4 and the mobile stations M1 and M1.
Since M3 is different from each of the frequencies F1 to F4 used at the timing of each of the slots S1 to S4, the mobile station M2 receives strong interference waves from each of the base stations of the cells “A” and “B”. It is unlikely that The mobile station M2
If the interference wave level at this time does not exceed a predetermined value,
Without changing the currently used frequency hopping sequence,
Continue to use as it is.

When the mobile station M1 changes the frequency hopping sequence Z1 to the frequency hopping sequence Z4 due to the interference wave level exceeding a predetermined value, the base station 20 of the cell "A" notifies each base station 20 is notified to a central control station (not shown) that manages 20. The central control station having received the notification transmits the information via the base stations 20 of the cells “A” and “B”,
When changing the frequency hopping sequence next time, the mobile station M2 and M3 are notified that a frequency hopping sequence different from the frequency hopping sequence Z4 used by the mobile station M1 is allocated from the frequency hopping sequences Z1 to Z7. I do. Note that the frequency hopping sequences Z1 to Z7 are
The mobile stations M1 to M3 are created so that the same frequency is not used at the same time.

Here, referring to FIG. 3, each mobile station 10 (M
1 to M3) will be described. FIG. 3 is a block diagram showing a configuration of the mobile station of the frequency hopping communication system according to the first embodiment of the present invention. The mobile station shown in FIG. 3 has a configuration in which an interference wave level detector 6 is further provided in the mobile station shown in FIG. Other configurations are the same as those shown in FIG. 11, and the same components are denoted by the same reference numerals. The operation process of the control unit 9 is different from that of the control unit 9 shown in FIG.

The interference wave level detector 6 detects the interference wave level of the mobile station based on the interference wave level information 6r input from the receiver 3, and sends the detection result to the controller 9 as interference wave level detection data 6t. Output. The control unit 9 determines whether or not the detected interference wave level exceeds a predetermined value based on the input interference wave level detection data 6t, and determines whether the interference wave level exceeds the predetermined value. If so,
A new frequency hopping sequence is selected, and an instruction to change to the selected frequency hopping sequence is output to the transmission / reception data processing unit 4 as a frequency hopping sequence change signal 9g. On the other hand, if the interference wave level does not exceed the predetermined value,
The control unit 9 continues to use the current frequency hopping sequence.

The base station 20 is notified of the frequency hopping sequence change signal 9g via the transmission / reception data processing unit 4, the transmission unit 2, the switching unit SW, and the antenna 1. The transmission / reception data processing unit 4 outputs the frequency hopping sequence data 9r to the control unit 9 as a response to the frequency hopping sequence change signal 9g. The control unit 9 determines the frequency data 9t based on the frequency hopping sequence data 9r, outputs the frequency data 9t to the synthesizer unit 5, and changes to the changed frequency hopping sequence. Note that the synthesizer unit 5 uses the timing signal 4g output from the transmission / reception data processing unit 4 based on the timing signal 4g.
The switching timing of each frequency is controlled.

Here, with reference to the flowchart shown in FIG. 4, a description will be given of a frequency hopping sequence change control processing procedure by the control unit 9 of the mobile station 10. In FIG.
First, the control unit 9 receives the interference wave level detection data 6t input from the interference wave level detection unit 6 and the frequency hopping sequence data 9r input from the transmission / reception data processing unit 4, and uses the frequency hopping sequence data 9r as a basis. To
Select a frequency hopping sequence (step S10)
1).

Thereafter, it is determined whether or not the interference wave level indicated by the interference wave level detection data 6t exceeds a predetermined value (step S102). If the interference wave level exceeds the predetermined value (step S102, YES), a new frequency hopping sequence to be used is selected from the beginning of the next frequency hopping cycle, and a frequency hopping sequence indicating the selected frequency hopping sequence The change signal 9g is output to the transmission / reception data processing unit 4 (step S103).

Thereafter, based on the frequency hopping sequence data 9r input from the transmission / reception data processing unit 4, a hopping frequency is determined by the selected frequency hopping sequence, and the frequency data 9t indicating the hopping frequency is output to the synthesizer unit 5. Then (step S104), transmission / reception processing is performed using the new frequency hopping sequence.

On the other hand, if the interference wave level does not exceed the predetermined value (step S103, NO), the currently used frequency hopping sequence is used as it is, and the frequency data 9t corresponding to the current frequency hopping sequence is stored. The output is output to the synthesizer unit 5 (step S104).

[0049] In the above-described first embodiment, based on the interference wave level detected by the mobile station 10, the mobile station 10
Although the frequency hopping sequence is changed,
The mobile station 10 may notify the base station 20 of the detection result of the interference wave level, and the base station 20 may change the frequency hopping sequence based on the detection result. Further, the mobile station 10 transmits the detection result of the interference wave level to the base station 2.
0, and the base station 20 may determine whether to change the frequency hopping sequence based on the detection result.

In the first embodiment, the mobile station 10 or the base station 20 uses the frequency hopping sequence used between the mobile station 10 and the base station 20 based on the interference wave level received by the mobile station 10. Judge whether or not to change, if the interference wave level exceeds a predetermined value, change the current frequency hopping sequence, and if the interference wave level does not exceed the predetermined value, use the current frequency hopping sequence as it is Therefore, in the mobile station 10 having a high interference wave level of the hopping frequency to be received, the frequency hopping sequence is changed, high quality communication can be performed, and the mobile station having a low interference wave level of the hopping frequency to be received is provided. 1
In the case of 0, stable quality communication can be performed continuously.

In this case, since the frequency hopping sequence is changed for the mobile station 10 receiving a large interference wave level, a higher frequency diversity effect can be obtained, and the required desired wave to the same frequency interference power ratio can be obtained. The communication can be performed at a higher reception level, and communication with high quality and reliability can be performed.

Embodiment 2 Next, a second embodiment of the present invention will be described. In the second embodiment, when the interference wave level of the hopping frequency is large, from the frequency hopping sequence group, no other mobile station uses,
The frequency hopping sequence number is changed to the frequency hopping sequence having the smallest value.

The system configuration and the configuration of a mobile station or a base station according to the second embodiment are the same as those of the first embodiment. However, the operation process of the control unit 9 is different. Here, with reference to the flowchart shown in FIG.
A description will be given of a frequency hopping sequence change control processing procedure performed by the control unit 9 of the mobile station 10 in FIG.

In FIG. 5, first, the control section 9 selects a frequency hopping sequence having a frequency hopping sequence number i = 0 based on the frequency hopping sequence data 9r (step S201). Thereafter, the control unit 9 determines whether or not the frequency hopping sequence corresponding to the selected frequency hopping sequence number i is being used by another mobile station (step S202).

When the frequency hopping sequence corresponding to the frequency hopping sequence number i is used by another mobile station (step S202, YES), the value of the frequency hopping sequence number i is incremented by one (step S2).
03), it is determined whether or not the value of the incremented frequency hopping sequence number i (= i + 1) exceeds the value of the frequency hopping sequence number N (step S).
204).

If the value of the frequency hopping sequence number i does not exceed the value of the frequency hopping sequence number N (step S204, NO), the flow shifts to step S202, where the incremented frequency hopping sequence number i is set to another value. It is determined again whether or not the mobile station is being used. On the other hand, if the value of the frequency hopping sequence number i exceeds the value of the frequency hopping sequence number N (step S204, YES), the currently used frequency hopping sequence number i is selected again (step S205). ,
It moves to step S206.

On the other hand, when the value of the frequency hopping sequence number i is not used by another mobile station (step S202,
No), a frequency hopping sequence number change signal 9g indicating an instruction to change to the frequency hopping sequence corresponding to the selected frequency hopping sequence number i is output to the transmission / reception data processing unit 4 (step S206), and then this frequency hopping is performed. Change to a series.

In the above-described second embodiment, the mobile station 10 performs the following operations based on the interference wave level detected by the mobile station 10.
Although the frequency hopping sequence is changed,
The mobile station 10 may notify the base station 20 of the detection result of the interference wave level, and the base station 20 may change the frequency hopping sequence based on the detection result. Further, the mobile station 10 transmits the detection result of the interference wave level to the base station 2.
0, and the base station 20 may determine whether to change the frequency hopping sequence based on the detection result.

In the second embodiment, as the frequency hopping sequence to be changed based on the interference wave level, a frequency hopping sequence having the smallest value of the frequency hopping sequence number and not being used by another mobile station is selected. As a result, the mobile station 10 can obtain a higher frequency diversity effect, can improve a required desired wave to co-frequency interference power ratio, and can perform communication at a higher reception level. Communication with high quality and high reliability.

When the frequency hopping sequence to be changed is used by all the other mobile stations 10, the currently used frequency hopping sequence is selected again. An increase in the level can be suppressed, the required desired wave to co-frequency interference power ratio can be improved, communication can be performed at a higher reception level, and communication with high quality and reliability can be maintained.

Embodiment 3 Next, a third embodiment of the present invention will be described. In the second embodiment described above,
When the interference wave level of the hopping frequency is large, a frequency hopping sequence having the smallest value of the frequency hopping sequence number is selected from the frequency hopping sequence group and is not used by another mobile station, and is changed. However, in the third embodiment, a frequency hopping sequence having the lowest interference wave level is selected based on the past history.

The system configuration and the configuration of the mobile station or the base station according to the third embodiment are the same as those of the first embodiment. However, the operation process of the control unit 9 is different. Here, referring to the flowchart shown in FIG.
A description will be given of a frequency hopping sequence change control processing procedure performed by the control unit 9 of the mobile station 10 in FIG.

In FIG. 6, first, the control unit 9 determines whether or not the interference wave level of the frequency hopping sequence has been measured before.
That is, it is determined whether or not the base station 20 has a past history regarding the interference wave level of the frequency hopping sequence (step S301). If there is a past history of the interference wave level (step S301, YES), a frequency hopping sequence number i having a frequency hopping sequence with the lowest interference wave level is selected based on this past history. (Step S302).

Thereafter, it is determined whether or not the frequency hopping sequence corresponding to the selected frequency hopping sequence number i is being used by another mobile station (step S303).
When the frequency hopping sequence corresponding to the frequency hopping sequence number i is used by another mobile station (step S
303, YES), a frequency hopping sequence having the value of the different frequency hopping sequence number i having the next lower interference wave level is selected (step S304), and the frequency hopping having the value of the selected frequency hopping sequence number i is selected. It is determined whether the sequence is a frequency hopping sequence having the highest interference wave level (step S305).

If the selected frequency hopping sequence is not the frequency hopping sequence having the highest interference wave level (step S 305, NO), the process proceeds to step 303 to determine whether this frequency hopping sequence is used by another mobile station. The process of determining again whether or not to repeat is repeated. On the other hand, when the selected frequency hopping sequence is the frequency hopping sequence having the highest interference wave level (step S305,
If YES, the frequency hopping sequence of the currently used frequency hopping sequence number i is selected again (step S306), and the process proceeds to step S308.

On the other hand, when the value of the frequency hopping sequence number i is not used by another mobile station (step S303,
(NO), a frequency hopping sequence number change signal 9g indicating an instruction to change to the frequency hopping sequence corresponding to the selected frequency hopping sequence number i is output to the transmission / reception data processing unit 4 (step S308), and then this frequency hopping is performed. Change to a series.

If there is no past history (step S
(301, NO), the frequency hopping sequence number i is incremented by one (step S307), and the
The process proceeds to 308, where a frequency hopping sequence corresponding to the frequency hopping sequence number i (= i + 1) that has been incremented by one is selected.

In the above-described third embodiment, the mobile station 10 performs the following operations based on the interference wave level detected by the mobile station 10.
Although the frequency hopping sequence is changed,
The mobile station 10 may notify the base station 20 of the detection result of the interference wave level, and the base station 20 may change the frequency hopping sequence based on the detection result. Further, the mobile station 10 transmits the detection result of the interference wave level to the base station 2.
0, and the base station 20 may determine whether to change the frequency hopping sequence based on the detection result.

In the third embodiment, the frequency hopping sequence to be changed based on the interference wave level is a frequency hopping sequence having the lowest interference wave level based on the past history, and is used by another mobile station. Since the unused frequency hopping sequence is selected, the mobile station 10 can obtain a higher frequency diversity effect, can improve the required desired wave to co-frequency interference power ratio, and Communication at a high reception level can be performed, and communication with high quality and reliability can be performed.

When there is no past history, the frequency hopping sequence number is incremented by one, and a frequency hopping sequence corresponding to the incremented frequency hopping sequence number, that is, a random frequency hopping sequence is selected. Therefore, the mobile station 10
A higher frequency diversity effect can be obtained,
The required desired wave to co-frequency interference power ratio can be improved, communication can be performed at a higher reception level, and communication with high quality and reliability can be performed.

Further, when the frequency hopping sequence to be changed is used by all the other mobile stations 10, the currently used frequency hopping sequence is selected again. An increase in the level can be suppressed, the required desired wave to co-frequency interference power ratio can be improved, communication can be performed at a higher reception level, and communication with high quality and reliability can be maintained.

Embodiment 4 Next, a fourth embodiment of the present invention will be described. In Embodiment 3 described above,
If the interference wave level of the hopping frequency is large, select and change the frequency hopping sequence that is not used by another mobile station and has the lowest interference wave level from the frequency hopping sequence group based on the past history In the fourth embodiment, the frequency hopping sequence having the smallest correlation with the currently used frequency hopping sequence is selected.

The system configuration and the configuration of a mobile station or a base station according to the fourth embodiment are the same as those of the first embodiment. However, the operation process of the control unit 9 is different. Here, with reference to the flowchart shown in FIG.
A description will be given of a frequency hopping sequence change control processing procedure performed by the control unit 9 of the mobile station 10 in FIG.

In FIG. 7, first, the control section 9 selects the frequency hopping sequence number i of the frequency hopping sequence having the smallest correlation with the currently used frequency hopping sequence based on the frequency hopping sequence data 9r (step S1). S401). Thereafter, it is determined whether or not the frequency hopping sequence corresponding to the selected frequency hopping sequence number i is used by another mobile station (step S4).
02).

If the frequency hopping sequence is being used by another mobile station (step S402, YES), the frequency hopping sequence number i having the next smallest correlation is selected (step S40).
3) It is determined whether or not the selected frequency hopping sequence is the frequency hopping sequence having the highest correlation (step 404). If it is not the frequency hopping sequence having the highest correlation (step S404, NO), the process moves to step S402, and the process of determining whether or not this frequency hopping sequence is used by another mobile station is repeated.

On the other hand, if the selected frequency hopping sequence is the frequency hopping sequence having the highest correlation (step S404, YES), the currently used frequency hopping sequence is selected again (step S40).
5) The process proceeds to step S406.

When the value of frequency hopping sequence number i is not used by another mobile station (step S402, NO)
Transmits a frequency hopping sequence number change signal 9g indicating an instruction to change to a frequency hopping sequence corresponding to the selected frequency hopping sequence number i.
(Step S406), and then change to this frequency hopping sequence.

[0078] In the above-described fourth embodiment, the mobile station 10 performs the following operations based on the interference wave level detected by the mobile station 10.
Although the frequency hopping sequence is changed,
The mobile station 10 may notify the base station 20 of the detection result of the interference wave level, and the base station 20 may change the frequency hopping sequence based on the detection result. Further, the mobile station 10 transmits the detection result of the interference wave level to the base station 2.
0, and the base station 20 may determine whether to change the frequency hopping sequence based on the detection result.

In the fourth embodiment, the frequency hopping sequence to be changed based on the interference wave level is a frequency hopping sequence having the smallest correlation with the currently used frequency hopping sequence and used by another mobile station. Since a frequency hopping sequence that is not performed is selected, the mobile station 10 can obtain a higher frequency diversity effect, can improve a desired desired signal to co-frequency interference power ratio, and can achieve a higher frequency diversity effect. Communication at the reception level can be performed, and communication with high quality and high reliability can be performed.

When the frequency hopping sequence to be changed is used by all the other mobile stations 10, the currently used frequency hopping sequence is selected again. An increase in the level can be suppressed, the required desired wave to co-frequency interference power ratio can be improved, communication can be performed at a higher reception level, and communication with high quality and reliability can be maintained.

[0081]

As described above, according to the present invention, the detecting means of the mobile station detects the interference wave level of each frequency at each frequency hopping cycle, and the control means detects the interference wave level detected by the detecting means. If the wave level exceeds a certain value,
Since the control to change the current frequency hopping sequence to another frequency hopping sequence is performed, the mobile station having a high interference wave level of the hopping frequency to be received is changed in the frequency hopping sequence to perform high quality communication. The mobile station having a low interference wave level of the hopping frequency to be received can continue to perform stable quality communication, and can further obtain a higher frequency diversity effect, and can obtain a desired desired wave to the same frequency interference. The power ratio can be improved, communication at a higher reception level can be performed, and communication with high quality and high reliability can be performed.

According to the next invention, the detection means of the mobile station detects the interference wave level of each frequency at each frequency hopping cycle, and the control means of the base station determines that the interference wave level detected by the detection means is a predetermined value. If the value is exceeded, since the control to change the current frequency hopping sequence to another frequency hopping sequence is performed, the mobile station having a large interference wave level of the hopping frequency to be received is changed in the frequency hopping sequence, High quality communication can be performed, and a mobile station having a low interference wave level of the hopping frequency to be received can continuously perform communication of stable quality.
Further, a higher frequency diversity effect can be obtained, a desired desired wave to co-frequency interference power ratio can be improved, communication can be performed at a higher reception level, and communication with high quality and reliability can be achieved. Is achieved.

According to the next invention, when the interference wave level detected by the detection means exceeds a predetermined value, the control means is a frequency hopping sequence not currently used by another mobile station, and Since the value of the frequency hopping sequence number is changed from the frequency hopping sequence group having the pre-allocated frequency hopping sequence number to the minimum frequency hopping sequence, control is performed.
A high frequency diversity effect can be obtained, a desired desired signal to co-frequency interference power ratio can be improved, communication can be performed at a higher reception level, and communication with high quality and reliability can be performed. It has the effect of being able to.

According to the next invention, when the interference wave level detected by the detection means exceeds a predetermined value, the control means refers to the history of the interference wave level and converts the current frequency hopping sequence into the The other mobile station is a frequency hopping sequence that is not currently used, and from the frequency hopping sequence group, so that the interference wave level is controlled to be changed to the minimum frequency hopping sequence.
A high frequency diversity effect can be obtained, a desired desired signal to co-frequency interference power ratio can be improved, communication can be performed at a higher reception level, and communication with high quality and reliability can be performed. It has the effect of being able to.

According to the next invention, when the interference wave level detected by the detection means exceeds a predetermined value, the control means changes the current frequency hopping sequence to a frequency hopping not currently used by another mobile station. It is a sequence, and since the correlation value with the current frequency hopping sequence is changed from the frequency hopping sequence group set in advance to the minimum frequency hopping sequence, control is performed so that a higher frequency diversity effect is achieved. It is possible to improve the required desired wave to co-frequency interference power ratio, perform communication at a higher reception level, and perform high-quality and reliable communication. .

According to the next invention, the mobile station detects the interference wave level of each frequency for each frequency hopping cycle in the detection step, and the interference wave level detected in the detection step is changed to the predetermined value by the change step. Is exceeded, the current frequency hopping sequence is changed to another frequency hopping sequence. Therefore, in a mobile station having a high interference wave level of the hopping frequency to be received, the frequency hopping sequence is changed, and high quality communication is performed. The mobile station having a low interference wave level of the hopping frequency to be received can continue to perform stable quality communication, and can further obtain a higher frequency diversity effect, and can obtain a desired desired wave pair. The same frequency interference power ratio can be improved, communication at a higher reception level can be performed, and quality and An effect that it is possible to perform reliable communication.

According to the next invention, by the detecting step,
The mobile station detects the interference wave level of each frequency for each frequency hopping cycle, by the change step, the base station,
When the interference wave level detected by the detection means exceeds a predetermined value, the current frequency hopping sequence is changed to another frequency hopping sequence. In the above, the frequency hopping sequence is changed, high-quality communication can be performed, and a mobile station having a low interference wave level of the hopping frequency to be received can continue to perform stable quality communication, and A frequency diversity effect can be obtained, a desired desired wave to co-frequency interference power ratio can be improved, communication can be performed at a higher reception level, and communication with high quality and reliability can be performed. This has the effect.

According to the next invention, the changing step is a frequency hopping sequence not currently used by another mobile station when the interference wave level detected in the detecting step exceeds a predetermined value, and Since the value of the frequency hopping sequence number is changed from the frequency hopping sequence group having the pre-assigned frequency hopping sequence number to the minimum frequency hopping sequence, a higher frequency diversity effect can be obtained. Thus, it is possible to improve the ratio of the desired desired wave to the same frequency interference power, to perform communication at a higher reception level, and to perform communication with high quality and reliability.

According to the next invention, in the history holding step, the base station holds the history of the past interference wave level for each frequency hopping sequence of the preset frequency hopping sequence group, and in the changing step, If the interference wave level detected by the detection step exceeds a predetermined value, refer to the history of the interference wave level, the current frequency hopping sequence, a frequency hopping sequence that is not currently used by other mobile stations, And, since the interference wave level is changed from the frequency hopping sequence group to the minimum frequency hopping sequence, a higher frequency diversity effect can be obtained, and the required desired wave to the same frequency interference power ratio can be obtained. Can be improved, communication at a higher reception level can be performed, and communication with high quality and reliability can be performed. There is an effect that.

According to the next invention, when the interference wave level detected by the detecting step exceeds a predetermined value by the changing step, the current frequency hopping sequence is changed to a frequency hopping not currently used by another mobile station. It is a sequence, and since the correlation value with the current frequency hopping sequence is changed to the minimum frequency hopping sequence from a preset frequency hopping sequence group, it is possible to obtain a higher frequency diversity effect. As a result, it is possible to improve the required desired wave to co-frequency interference power ratio, perform communication at a higher reception level, and perform high-quality and reliable communication.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of a frequency hopping communication system according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of changing a frequency hopping sequence.

FIG. 3 is a block diagram showing a configuration of a mobile station shown in FIG.

FIG. 4 is a flowchart showing a frequency hopping sequence change control process performed by a control unit of the mobile station shown in FIG.

FIG. 5 is a flowchart illustrating a frequency hopping sequence change control process performed by a control unit of a mobile station in the frequency hopping communication system according to the second embodiment of the present invention.

FIG. 6 is a flowchart illustrating a frequency hopping sequence change control process performed by a control unit of a mobile station in a frequency hopping communication system according to Embodiment 3 of the present invention.

FIG. 7 is a flowchart illustrating a frequency hopping sequence change control process performed by a control unit of a mobile station in a frequency hopping communication system according to Embodiment 4 of the present invention.

FIG. 8 is a diagram showing an outline of a conventional frequency hopping communication system.

FIG. 9 is a diagram illustrating an example of a frequency hopping sequence.

FIG. 10 is a timing chart of frequency hopping in each mobile station.

FIG. 11 is a block diagram illustrating a configuration of the mobile station illustrated in FIG.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 antenna, 2 transmission section, 3 reception section, 4 transmission / reception data processing section, 5 synthesizer section, 6 interference wave level detection section, 9 control section, 10, M1 to M3 mobile station, 20
Base station, 30 wireless cells, SW switching unit, Z1-Z7
Frequency hopping sequence.

Claims (10)

[Claims] 1. A frequency hopping communication system that performs communication between a base station and a mobile station while performing frequency hopping based on a predetermined frequency hopping sequence, wherein the mobile station performs interference of each frequency every frequency hopping cycle. Detection means for detecting a wave level, and control means for performing control to change the current frequency hopping sequence to another frequency hopping sequence when the interference wave level detected by the detection unit exceeds a predetermined value, A frequency hopping communication system, comprising: 2. A frequency hopping communication system for performing communication between a base station and a mobile station while performing frequency hopping based on a predetermined frequency hopping sequence, wherein the mobile station performs interference of each frequency every frequency hopping cycle. The base station, comprising: a control unit that performs control to change the current frequency hopping sequence to another frequency hopping sequence when the interference wave level detected by the detection unit exceeds a predetermined value. A frequency hopping communication system characterized by comprising means. 3. The control unit, when the interference wave level detected by the detection unit exceeds a predetermined value, a frequency hopping sequence that is not currently used by another mobile station, and a frequency assigned in advance. 2. A control for changing a frequency hopping sequence number from a group of frequency hopping sequences having a hopping sequence number to a frequency hopping sequence having a minimum value.
Or the frequency hopping communication system according to 2. 4. The base station further includes a history holding unit that holds a history of past interference wave levels for each frequency hopping sequence of a preset frequency hopping sequence group, wherein the control unit includes: When the detected interference wave level exceeds a predetermined value, referring to the history of the interference wave level, the current frequency hopping sequence is a frequency hopping sequence not currently used by another mobile station, and the frequency hopping sequence 3. The frequency hopping communication system according to claim 1, wherein control is performed to change the interference wave level from the sequence group to a frequency hopping sequence having a minimum interference wave level. 5. The control unit, when the interference wave level detected by the detection unit exceeds a predetermined value, the current frequency hopping sequence is a frequency hopping sequence that is not currently used by another mobile station, 3. The frequency hopping communication system according to claim 1, wherein control is performed to change a frequency hopping sequence having a minimum correlation value with a current frequency hopping sequence from a preset frequency hopping sequence group. 6. A frequency hopping communication method for performing communication between a base station and a mobile station while performing frequency hopping based on a predetermined frequency hopping sequence, wherein the mobile station performs interference of each frequency every frequency hopping cycle. A detection step of detecting a wave level, and a change step of changing the current frequency hopping sequence to another frequency hopping sequence when the interference wave level detected by the detection step exceeds a predetermined value. Frequency hopping communication method. 7. A frequency hopping communication method for performing communication between a base station and a mobile station while performing frequency hopping based on a predetermined frequency hopping sequence, wherein the mobile station generates an interference wave of each frequency every frequency hopping cycle. A detecting step of detecting a level, and the base station, when the interference wave level detected by the detecting step exceeds a predetermined value, a changing step of changing the current frequency hopping sequence to another frequency hopping sequence. A frequency hopping communication method comprising: 8. The changing step includes the step of: when the interference wave level detected by the detection means exceeds a predetermined value, a frequency hopping sequence not currently used by another mobile station, and a frequency allocated in advance. 8. The frequency hopping communication method according to claim 6, wherein the value of the frequency hopping sequence number is changed to the minimum frequency hopping sequence from among the frequency hopping sequence group having the hopping sequence number. 9. The base station further includes a history holding step of holding a history of past interference wave levels for each frequency hopping sequence of a preset frequency hopping sequence group, and wherein the changing step includes: When the detected interference wave level exceeds a predetermined value, referring to the history of the interference wave level, the current frequency hopping sequence is a frequency hopping sequence that is not currently used by other mobile stations, and the frequency 8. The frequency hopping communication method according to claim 6, wherein the frequency of the hopping sequence is changed to a frequency hopping sequence having a minimum interference wave level. 10. The changing step, when the interference wave level detected by the detecting step exceeds a predetermined value, the current frequency hopping sequence is a frequency hopping sequence that is not currently used by other mobile stations, 8. The frequency hopping communication method according to claim 6, wherein a correlation value with a current frequency hopping sequence is changed to a frequency hopping sequence having a minimum value from a preset frequency hopping sequence group.