WO1999034630A1

WO1999034630A1 - Method of assigning and selecting radio channel

Info

Publication number: WO1999034630A1
Application number: PCT/JP1998/005859
Authority: WO
Inventors: Yasunori Suzuki; Toshio Nojima
Original assignee: Ntt Mobile Communications Network Inc.
Priority date: 1997-12-25
Filing date: 1998-12-24
Publication date: 1999-07-08
Also published as: JP3795536B2; CA2281578A1

Abstract

A method of assigning a plurality of radio channels to realize a radio mobile communication system in which a plurality of radio channels are simultaneously used in each of a plurality of zones (1-7) that form an area (8) where radio channels are repeatedly reused. At least one of the radio channels is assigned for preferential use in each zone, while the other channels are assigned for use in any adjacent zones. A mobile station (10) selects a first radio channel at a frequency (f1) that has been assigned to a visited zone (1). The mobile station then detects unused radio channels at different frequencies (f2-f7) assigned to adjacent zones to select one as a second channel, informs the base station in the visited zone (1) of the selected channels, and uses the radio channels to establish the connection to the base station of the visited zone (1).

Description

Description Wireless channel assignment and selection method

The present invention relates to a radio channel allocation method used for a mobile radio communication system using a plurality of radio channels simultaneously, and a method of selecting an allocated radio channel. Background art

In order to increase the frequency utilization efficiency of the conventional mobile radio communication system, a method of assigning a radio channel in the mobile radio communication system is being studied. A method of fixedly assigning a radio channel to each zone (Fixed Channel Assignment FCA) A method of dynamically allocating a wireless channel in a plurality of zones (Dynamic Channel Assignment: DCA) is known. In addition, a wireless channel assignment method using these simultaneously has been proposed.

FCA has been practically used in mobile radio communication systems. For example, there are an analog NTT system and a digital mobile communication system (Personal Digital Cellular: PDC). In addition, DCA has been put into practical use without a digital cord.

By the way, in such a mobile communication system based on FCA, the setting of the radio channel between the base station and the mobile station is performed by selecting an empty radio channel from the radio channels assigned to the base station in the zone where the mobile station is located. A channel was selected, and a mobile radio line was set up with the selected radio channel. The radio channel assigned to each base station may cause interference with the radio channels of other base stations. For this mobile radio communication system, it is assumed that a single radio channel is mainly used.

On the other hand, recently, one mobile station has adopted a mobile radio communication system using a plurality of radio channels. In this communication method using multiple radio channels, in order to achieve high-speed transmission and high-quality transmission, a mobile station uses multiple radio channels assigned to the base station in the zone to which it belongs (the zone in which it is located). I have.

However, even if multiple channels are used, the wireless channel allocation method in the repetitive zone is different only in that it only uses the radio channel assigned to be used preferentially in the visited zone. As was essentially the same.

For this reason, compared to the case of using a single wireless channel, the overall frequency effective utilization efficiency (the product of the utilization rate on the frequency axis and the utilization rate on the spatial axis) is higher when using multiple radio channels simultaneously. ) Decreased.

An object of the present invention is to allocate radio channels that do not reduce the overall frequency utilization efficiency even when one mobile station uses a plurality of radio channels at the same time as compared to a case where a single mobile station uses a single radio channel, and It is to provide a selection method.

Disclosure of the invention

In order to achieve the above object, the present invention provides a mobile radio communication system for realizing a mobile radio communication system by simultaneously using a plurality of radio channels in each of a plurality of zones constituting a repetition area of wireless channels. In the radio channel allocation method for the zones, at least one of the plurality of radio channels is allocated to a radio channel that can be used preferentially in each zone, and Among the line channels, a plurality of radio channels other than the radio channel that can be used preferentially in each zone are assigned to each of the above zones as radio channels that can also be used in a zone adjacent to each zone.

In this mobile radio communication system, by allocating a radio channel in this way, at least one of a plurality of radio channels used simultaneously by the mobile station is allocated a radio channel that can be used preferentially in the visited zone. The remaining radio channels of the plurality of radio channels can be used by selecting an unused radio channel from among the radio channels that can be used preferentially in the zone adjacent to the visited zone. Can be used in the in-zone zone.

As a result, even if a plurality of wireless channels are used at the same time, the frequency use efficiency in the repeated zone does not decrease.

The wireless channel assignment method of the present invention can be applied irrespective of whether the wireless channel is set by frequency division, time division, or code division, or any combination thereof.

If the transmission quality is degraded due to the same channel interference while using a wireless channel with priority in an adjacent zone, the mobile unit will handover to an empty wireless channel with priority in another zone. Can be used. This allows multiple radio channels to be used simultaneously.

In order to realize a mobile radio communication system by simultaneously using a plurality of radio channels in each of a plurality of zones constituting a repetitive area for wireless channel repetition of the present invention, each zone exists in each of the plurality of zones. In the radio channel selection method performed by the mobile station, the mobile station selects at least one of the plurality of radio channels as the radio channel assigned to the zone where the mobile station is located, and selects the plurality of radio channels. Of these, radio channels other than the radio channel assigned to the zone where the mobile station is located are assigned to a plurality of zones adjacent to the zone where the mobile station is located. Selected as the radio channel assigned to the local zone and used in the visited zone.

The process in which the mobile station selects a radio channel in the adjacent zone includes (1) a process of detecting the reception level of the radio channel in the adjacent zone, and (2) a process of measuring co-channel interference from the detected reception level. (3) a step of comparing the measured reception level with a predetermined value; (4) if the compared reception level is equal to or higher than a predetermined value, the channel is located between the base station and the mobile station in the local zone. And (5) selecting a different radio channel in an adjacent zone when the compared reception level is equal to or lower than a predetermined value.

Then, the step of selecting a radio channel in a zone adjacent to the mobile station may further include a step of controlling the transmission output of the base station and the mobile station of the set radio channel to be close to a predetermined reception sensitivity. Good. The mobile station that implements the above-described radio channel selection method is a mobile station.

As described above, the radio channel assignment method and the selection method of the present invention have the following effects.

(1) In mobile communication using multiple wireless channels, the frequency utilization efficiency can be improved compared to the conventional wireless channel allocation method,

(2) High-speed transmission becomes possible,

(3) Applicable to existing mobile radio communication systems using a single carrier, and

(4) For mobile stations, it can be applied by simple extension of the line control of existing mobile stations. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a wireless zone configuration diagram illustrating a wireless channel assignment method according to the present invention. FIG. 2 is a simplified zone configuration diagram of the embodiment of FIG.

FIG. 3 is a diagram showing the relationship between FIG. 3A and FIG. 3B.

FIG. 3A and FIG. 3B are block diagrams showing the configuration of a mobile station relating to the assignment of a wireless channel according to the present invention.

FIG. 4 is a flowchart showing a process of selecting a mobile station for explaining the radio channel selection method of the present invention.

FIG. 5 is a flowchart showing another process of the selection in FIG.

FIGS. 6A and 6B are diagrams showing a case where radio channel assignment is applied to frequency division.

FIGS. 7A and 7B are diagrams showing a case where radio channel assignment is applied to time division.

FIGS. 8A and 8B are diagrams showing a case where radio channel assignment is applied to code division.

FIG. 9A and FIG. 9B are diagrams showing a case where the assignment of the wireless channel is set by simultaneously using the frequency division and the time division.

FIG. 10A and FIG. 10B are diagrams showing a case where radio channel assignment is set using time division and code division simultaneously.

FIG. 11A and FIG. 11B are diagrams showing a case where the assignment of the wireless channel is set by simultaneously using code division and frequency division.

FIG. 12A and FIG. 12B are diagrams showing a case where frequency division, time division, and code division are applied to a wireless channel set by using them simultaneously. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, with reference to the drawings, the assignment of the wireless channel according to the present invention will be described in each zone. A description will be given of a method of allocating the wireless channels separately to authorized channels, and a method of selecting a plurality of wireless channels allocated to each zone by a mobile station located in the present invention.

Figure 1 shows the assignment of wireless channels. The switching center 108 that controls the inter-use repetition area 100 of wireless channels consisting of a total of seven zones, each having a base station, and the base stations connected to it. 10 1 to 10 7) and an example of the state of mutual connection between exchanges.

In FIG. 1, the switching center 108 and the base stations (101 to 107) in each zone are connected by a dedicated line 109. The dedicated line 109 is a normal communication line. In the radio channel assignment method according to the present invention, the radio channel number used for each base station (101 to 107) is changed from the exchange 108 to a dedicated line 1010 by a predetermined radio channel assignment plan. Specifically, each base station is instructed via 9.

In FIG. 1, such a wireless channel is divided by frequency division (FDMA:

Frequency division multiple access).

For example, when 800 MHz band FDMA wireless channels are prepared for 60 channels, the wireless channel numbers assigned to each zone are as shown in Table 1 as an example. Here, each wireless channel has a 25 KHz bandwidth, and the frequency interval of each wireless channel is 50 KHz. For example, if the wireless channel number 1 is assigned to 800.500 MHz, the wireless channel number 60 becomes 803.00 OMHz. Table 1 Base station numbers Assigned wireless channel numbers

1 1,2,3,4,5

2 10, 11, 12, 13, 14, 15, 15, 16, 17, 18, 19, 20

3 30,31,32,33,34,35,36,37,

4, 6, 7, 8, 9, 21, 22, 23, 24, 25, 26, 27, 28, 29

5 38, 39,40, 41, 42, 43, 44, 45, 46

6 50,51,52,53,54,55,56,57,58,59,60

7 47,48,49 According to Table 1, radio channel numbers 1 to 5 are assigned to base station number 1. This is a 5 carrier (carrier) from 800.500 MHz to 800.250 MHz. For the assignment of such radio channels to each zone, a correspondence table as shown in Table 1 is stored in the exchange shown in FIG. The allocation table stored in the exchange 108 may be stored in a higher-level exchange that collectively manages a plurality of exchanges. The storage method is realized by software or the like in a base station control device in the exchange, for example.

Now, the plurality of radio channels allocated to each zone are efficiently selected between the mobile station and the base station so that the frequency use efficiency does not decrease, and the line is set. This will be described below. For the sake of simplicity, a case will be described below with reference to FIG. 2 in which it is assumed that only two channels are used at the same time for the radio channels allocated to each zone by frequency division.

Now, the wireless communication zone consists of seven zones (zones 1 to 7) as shown in Fig. 2. Zone 1 has Zones 2 to 7 adjacent to each other, forming a repeating area 8. In addition, base stations in each zone are assigned frequencies fl to f7, respectively, and have a radio channel that can be used preferentially by a mobile station in the area, and a priority to other zones. 6 wireless channels are assigned. For example, regarding zone 1, the radio channel having frequency f1 is set as the radio channel having priority in its own zone, and the channel having frequency f2 to f7 is set in each of the other zones (zones 2 to 7). The base station 10 of the zone 1 is allocated as a wireless channel having a priority, and facilities for communicating using these wireless channels are prepared. The mobile station in each zone has the function of communicating with the wireless channel with priority for the zone in which it is located, and the function of simultaneously communicating with the wireless channel with priority for other zones. .

As a method of knowing the radio channel having the priority in the in-zone zone, for example, since the base station broadcasts its own identification number on the control channel, the mobile station uses this identification number. By receiving the control channel including the control channel, the wireless channel having the priority can be known from the identification number.

Now, as described above, the mobile station, which is located in one zone, determines how the plurality of radio channels allocated in this manner are selected by the mobile station. The case where the lines are set simultaneously will be described together with an example of the configuration.

The mobile station as a mobile station shown in FIG. 3A and FIG. 3B has two sets of transmitting / receiving sections in the radio section. The first receiving unit 110 and the second receiving unit 120 are high-frequency amplifiers 112, 122, receiving mixers 114, 124, intermediate amplifiers 114, 126, and demodulators, respectively. It consists of 118 and 128, each receiving a radio channel of a different frequency and converting it to a baseband signal. You. The first transmission section 13 0 and the second transmission section 140 consist of modulators 13 6 and 14 6, transmission mixers 13 4 and 14 4, and transmission power amplifiers 13 2 and 14 2. Is done. First transmitting section 130 and second transmitting section 140 transmit transmission signals from baseband processing section 150 on radio channels having different frequencies. The frequency synthesizer 103 includes the reception mixers 114 and 124 of the first and second receiving units (110 and 120), and the first and second transmitting units (130 and 120). The corresponding frequencies are sent to the transmission mixers 134, 144 of (140) to determine the respective reception frequencies and transmission frequencies.

The reception signal from the radio unit and the transmission signal to the radio unit are processed by the reception signal processing circuit 152 and the transmission signal processing circuit 154 of the baseband signal processing unit 150. The signal from the reception signal processing circuit 152 is transmitted to the user of the mobile device by the receiver 170. Signals from the transmitter 180 and the like are processed by the transmission signal processing circuit 154 and sent to the radio unit. The control unit includes a control circuit 160 including a display key 190, a CPU, and the like, and controls the baseband signal processing unit 150 and the wireless unit. The baseband processing unit has a transmission / reception timing control circuit, which sends a timing signal to the control unit.

First, a brief description will be given of how a mobile station having such a configuration and a base station in which the mobile station is located efficiently use a wireless channel with reference to FIG. I do.

The mobile station 10 residing in the zone 1 sets up a line in the zone 1 with the first radio channel of the frequency f 1 having priority. The setting of this line is performed in the same manner as the setting of the conventional wireless channel between the mobile station existing in the normal serving zone and the base station in the serving zone.

Next, the mobile station 10 observes co-channel interference of other radio channels, A wireless channel and a line setting below a predetermined value are set. For the setting of this radio channel, a radio channel having a priority in another zone is also possible.

At this time, for example, the mobile station 10 can set up a line between the second radio channel of the frequency f2 having a priority in zone 2 and the base station in zone 1 where the mobile station is located ^. In this case, the mobile station first notifies the base station in zone 1 in which the mobile station is to use the second wireless channel. The base station in zone 1 uses the second radio channel to set up the line for mobile stations in zone 1.

The mobile station 10 uses the first and second radio channels. The mobile station 10 always observes co-channel interference on the second radio channel. Then, if the line quality of the second wireless channel is degraded during communication, the mobile station further hands over to a wireless channel having priority over another zone. Here, for example, handover is performed to a wireless channel having priority in the third zone. In this case as well, the mobile station notifies the base station of the visited zone of the wireless channel to be handed over, and sets the wireless channel having priority over zone 3 of the visited base station as the second wireless channel. Use this to set the line.

The reason why the deterioration of the line quality is observed will be described. Radio channels that have priority in other zones can be used preferentially in priority zones. If a wireless channel with priority in another zone is used simultaneously in two or more zones, for example, the own zone and another zone, the channel quality is degraded due to co-channel interference. When a mobile station using a non-priority wireless channel in the visited zone detects line quality deterioration due to co-channel interference, it hands over the second channel used and hands over to another wireless channel. I do.

Through this series of operations, the mobile station always uses two radio channels. Can be.

In the above case, the case where two wireless channels are set has been described, but three or more wireless channels can be set in the same manner.

In the following, the channel selection operation of this mobile station will be described in more detail.

As described above, the mobile station 10 first selects a radio channel of frequency ί 1 assigned to the base station in zone 1 as the first radio channel. Then, it communicates with the base station and determines its radio channel. For example, the first transmitting unit 130 and the first receiving unit 110 in FIGS. 3A and 3B are set to this frequency. Control the frequency synthesizer 103.

Next, the mobile station 10 detects an unused wireless channel having a frequency different from that of the visited zone in the adjacent zone. This is performed using second transmitting section 140 and second receiving section 120 in FIGS. 3A and 3B. As shown in FIG. 2, it is assumed that a vacancy is found in the radio channel of the adjacent zone 2 at the frequency f 2. This is selected as the second wireless channel, and the selected wireless channel is communicated to the serving base station, and this wireless channel is set as the wireless channel with the serving zone base station. This allows the mobile station to use the two radio channels simultaneously as the radio channels of the visited zone. Since an unused radio channel is used, the frequency use efficiency of the mobile radio communication system does not decrease.

As described above, since the wireless channel in the zone where the mobile station is located and the wireless channel in the adjacent zone are used at the same time, efficient wireless channel selection can be performed.

In this radio channel selection method, the first selection is to select a radio channel assigned in advance to the zone in which the mobile station is located. The second choice is next Select the wireless channel assigned to the contact zone in advance as the wireless channel of the visited zone.

However, the selection of the second wireless channel causes the above-mentioned co-channel interference between the visited zone and the adjacent zone, which is a dominant factor in the deterioration of the quality of the wireless channel. In order to avoid this co-channel interference, in the radio channel selection method according to the present invention, the radio channel setting is set by the visited zone base station and the mobile station as the visited zone radio channel with respect to the empty radio channel of the adjacent zone. At this time, the mobile station and the base station perform transmission power control to reduce co-channel interference to adjacent zones.

Thereafter, if the second selected radio channel suffers from deterioration of the line quality due to the same channel interference, the mobile station immediately performs handover to a radio channel in a different adjacent zone.

According to the series of processes of the present invention, mobile radio communication using a plurality of radio channels simultaneously can be performed without reducing the frequency utilization efficiency while avoiding the influence of co-channel interference.

The above-described series of operations will be described in detail with reference to the flowchart shown in FIG. Here, a case of radio channel selection performed by a mobile station using two radio channels simultaneously as in FIG. 2 will be described.

FIG. 4 shows a process in which the mobile station 10 makes a second selection after selecting the first radio channel. This first wireless channel is a wireless channel allocated to the visited zone, and is the same as the conventional wireless channel selection, and therefore the description is omitted.

First, as a second wireless channel, a free wireless channel in a zone adjacent to the visited zone is detected by the mobile station 10 (S202). Free wireless channel from base station The co-channel interference in the channel is measured (S204), and it is determined whether the power ratio to the measured value is equal to or greater than a predetermined value (S206).

If the result of the determination is that the value is equal to or greater than the predetermined value, the idle radio channel is notified to the serving base station (S208). The mobile station 10 performs subsequent communication with the base station in the area where the mobile station 10 is located. Thereafter, the mobile station 10 and the base station in the visited zone mutually control the transmission power of the second radio channel (S210), and control the transmission power to near the required reception sensitivity (S211). 2). At this time, the transmission power control on the mobile station side is performed by the control circuit 160 with respect to the transmission power amplifier 144 of FIG. 3B. This control may be a low-speed control about once every few seconds. The range of transmission output control requires a wide dynamic range from the maximum transmission output to the vicinity of required reception sensitivity, but the accuracy of transmission output control of several dB is sufficient. The purpose of transmission power control is to reduce co-channel interference. This completes the selection of the second radio channel (S2114).

When the result of the determination in S 206 is equal to or less than a predetermined value, the mobile station detects a wireless channel in a different adjacent zone (S 202). Thereafter, the mobile station selects a radio channel to be used by the above-described radio channel selection processing.

By the way, interference is measured for the second wireless channel even during communication. This processing will be described with reference to the flowchart of FIG. In the flowchart of FIG. 5, after the selection, the same channel interference is measured together with the transmission power control (S220). If the result of the measurement is equal to or less than the predetermined value, the wireless channel is continued to be used (Y2S in S222).

If the interference is equal to or greater than a predetermined value, the handover is performed on an empty channel in another adjacent zone. The process of selecting an empty channel is similar to the process of selecting a channel in FIG.

The above process communicates with the base station over two radio channels as described in FIG. The case of trust has been described. If the mobile station requires two or more radio channels, the above-described process of the empty channel is performed.After the above-mentioned second radio channel is selected, the same radio channel selection is performed for the required number of radio channels. Do. As a result, a plurality of wireless channels can be allocated to the mobile station without lowering the frequency use efficiency.

The wireless channel allocation method according to the present invention and the specific method of selecting the allocated wireless channel have been mainly described for the case where the wireless channel is configured by frequency division. The allocation method is not limited to this, and various wireless communication systems, for example, a TDMA (Time Division Multiple Access) system in which channels are formed by time-division slots, and a CDMA (Code The allocation of the wireless channel of the present invention is also applied to various multiplexing systems such as the Division Multiple Acces s) system in the same manner as described above.

Hereinafter, the application of the wireless channel assignment method of the present invention will be described for each wireless channel configuration, including again the configuration based on frequency division.

(Frequency division)

FIGS. 6A and 6B show a case where the present invention is applied to a frequency-divided wireless channel. FIG. 6A is the same as FIG. 2 and shows an example in which one repetition zone is composed of seven zones. As shown in FIG. 6B, the radio channel is set by dividing the frequency band. In FIG. 6B, a radio channel of a certain frequency band is preferentially assigned to the first zone, and a mobile station located in the first zone has priority.

Mobile stations are trying to use two radio channels simultaneously. First, a carrier with priority in zone 1 is used as the first radio channel. The second radio channel is, for example, the carrier for which Zone 3 has priority, Select the channel with the lowest interference value and use it in zone 1. Then, when the line quality of the second channel is degraded, for example, handover is performed to a carrier in which zone 6 has priority.

(Time division)

Figures 7A and 7B show the case of application to time-divided wireless channels. FIG. 7A is the same as FIG. 6A, and shows an example in which one zone is composed of seven zones. As shown in FIG. 7B, the radio channel is composed of time slots, and each zone has a priority time slot.

Mobile stations are trying to use two radio channels simultaneously. First, a time slot with a priority in zone 1 is used as the first radio channel. A time slot with priority in zone 3 is used in zone 1 as the second radio channel. Then, when the quality of the line of the second channel is deteriorated, a handover to a time slot (for example, a radio channel of zone 6) having a priority in another zone is performed.

(Code division)

FIGS. 8A and 8B show a case where the present invention is applied to a code-divided wireless channel. FIG. 8A shows an example in which one repetition zone is composed of seven zones, similarly to FIG. 6A. As shown in FIG. 8B, the radio channel is configured by using a plurality of orthogonal codes, multiplying the orthogonal code by a signal, and spreading the signal.

Mobile stations are trying to use two radio channels simultaneously. First, the first wireless channel uses an orthogonal code having a priority in zone 1. The second radio channel uses an orthogonal code having priority in zone 3 in zone 1. If the line quality on this radio channel degrades, handover to another radio channel with priority in another zone (for example, a zone 6 radio channel). Bar can be.

(Frequency division and time division)

FIGS. 9A and 9B show a case where the present invention is applied to a wireless channel set by simultaneously using frequency division and time division. FIG. 9A shows an example in which, as in FIG. 6A, one repetition zone is composed of seven zones. As shown in Fig. 9B, the radio channel is set by dividing it by frequency and time slot.

Mobile stations are trying to use two radio channels simultaneously. First, the first wireless channel uses a carrier and a time slot with priority in zone 1. For the second radio channel, the carrier channel and time slot that have priority in zone 3 are used in zone 1. If the line quality of this radio channel degrades, handover to another radio channel with priority in another zone (for example, the radio channel in zone 6) is possible.

(Time division and code division)

FIGS. 10A and 10B show a case where the present invention is applied to a wireless channel set by simultaneously using time division and code division. FIG. 1OA shows an example in which, as in FIG. 6A, one repetition zone is composed of seven zones. As shown in FIG. 10B, the radio channel is set by dividing it by time slots and orthogonal codes.

Mobile stations are trying to use two radio channels simultaneously. First, as the first wireless channel, a time slot having priority in zone 1 and a wireless channel of orthogonal code are used. For the second radio channel, for example, a time slot having a priority in zone 3 and an orthogonal code radio channel are used in zone 3. If the line quality of this radio channel deteriorates, handover to another radio channel with priority in another zone (for example, the radio channel in zone 6) is possible.

(Code division and frequency division) FIGS. 11A and 11B show a case where the present invention is applied to a wireless channel set using code division and frequency division simultaneously. FIG. 11A shows an example in which one repetition zone is composed of 7 zones, similarly to FIG. 6A. As shown in FIG. 11B, the radio channel is divided and set by the orthogonal code and the frequency.

Mobile stations are trying to use two radio channels simultaneously. First, the first radio channel uses the orthogonal code and carrier radio channel that have priority in zone 1. The second radio channel uses, for example, a radio channel of an orthogonal code and a carrier having priority in zone 3 in zone 1. If the line quality of this radio channel degrades, it can hand over to another radio channel that has priority in another zone (for example, a zone 6 radio channel).

(Frequency division, time division and code division)

Figures 12A and 12B show the case of application to a wireless channel set using frequency division, time division, and code division simultaneously. FIG. 12A shows an example in which one zone is composed of seven zones as in FIG. 6A. As shown in Fig. 12B, the radio channel is set by dividing it by frequency, time slot and orthogonal code.

Mobile stations are trying to use two radio channels simultaneously. First, the first wireless channel uses a carrier with priority in zone 1, a time slot, and an orthogonal code. The second radio channel uses, for example, a carrier having a priority in zone 3, a time slot, and an orthogonal code in zone 1. If the line quality of this radio channel degrades, it can hand over to another radio channel that has priority in another zone (for example, the radio channel in zone 6).

As described above, according to the wireless channel assignment method of the present invention, Applies regardless of how the radio channel is configured, i.e., whether it is configured by frequency division, time division, code division, or any combination thereof can do.

Further, the mobile station can set a plurality of radio channels without being limited to the radio channel assigned preferentially to the zone in which the mobile station is located, so that the frequency use efficiency can be improved.

Claims

The scope of the claims

1. In order to implement a mobile radio communication system by simultaneously using a plurality of radio channels in each of a plurality of zones constituting a repetitive area of radio channels, the radio channel allocation method for the plurality of zones includes:

At least one of the plurality of radio channels is assigned to a radio channel that can be used preferentially in each of the zones; and

Of the plurality of wireless channels, a plurality of wireless channels other than the wireless channel that can be used preferentially in each zone are assigned to each of the zones as a wireless channel that can also be used in a zone adjacent to each zone.

Wireless channel allocation method.

2. The wireless channel assignment method according to claim 1, wherein the plurality of wireless channels are configured by frequency division.

3. The wireless channel assignment method according to claim 1, wherein the plurality of wireless channels are configured by time division.

4. The wireless channel assignment method according to claim 1, wherein the plurality of wireless channels are configured to be distinguished by orthogonal codes.

5. The wireless channel allocation method according to claim 1, wherein the plurality of wireless channels are configured by simultaneously using frequency division and time division.

6. The wireless channel assignment method according to claim 1, wherein the plurality of wireless channels are configured by simultaneously using time division and code division.

7. The wireless channel according to claim 1, wherein the plurality of wireless channels are configured by simultaneously using frequency division and code division. Assignment method.

8. The radio channel assignment method according to claim 1, wherein the plurality of radio channels are configured by simultaneously using frequency division, time division, and code division.

9. Mutual use of wireless channels In order to realize a mobile wireless communication system by simultaneously using a plurality of wireless channels in each of a plurality of zones constituting a repetitive area, a mobile station in each of the plurality of zones performs the method. In the wireless channel selection method,

The mobile station selects at least one of the plurality of radio channels as a radio channel assigned to a zone where the mobile station is located, and

Of the plurality of radio channels, radio channels other than the radio channel assigned to the zone where the mobile station is located are assigned to a plurality of zones adjacent to the zone where the mobile station is located. Select as channel and use in visited zone

A method for selecting a wireless channel.

10. Selection of a radio channel in a zone adjacent to the mobile station is as follows:

(1) a step of detecting the reception level of the wireless channel in the adjacent zone; (2) a step of measuring the same channel interference from the detected reception level; and (3) comparing the measured reception level with a predetermined value. Process

(4) setting the wireless channel of the channel between the base station and the mobile station in the visited zone if the compared reception level is equal to or higher than a predetermined value;

(5) when the compared reception level is equal to or less than a predetermined value, returning to (1) and selecting a different radio channel of the adjacent zone;

10. The wireless channel selection method according to claim 9, comprising:

1 1. The selection of the radio channel in the zone adjacent to the mobile station further comprises: A step of controlling the transmission output of the base station and the mobile station on the radio channel set between the base station and the mobile station in the visited zone to be close to a predetermined reception sensitivity

10. The wireless channel selection method according to claim 10, comprising:

12. The radio channel selection method according to any one of claims 9 to 11, wherein the mobile station that performs the radio channel selection method is a mobile station.