JPH10276468A - Radio communication channel allocating method and radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the frequency utilization rate of a radio communication channel and to attain the reduction of loss probability by allocating radio communication channels less than the number of radio communication channels to mobile stations corresponding to plural communication classes requested from the mobile stations. SOLUTION: The mobile station transmits a request signal requesting the allocation of radio communication channel designating any communication class to be used out of plural communication classes. Then, a base band signal processing part 22 at a radio base station decodes the requested communication class from this request signal, and a storage part 25 stores the maximum number of allocation channels and required communication quality corresponding to the plural communication classes previously requested by the mobile station. Further, based on these decoded result and stored information, a processing part 24 allocates the radio communication channels, which are less than the maximum number of allocation channels and less than the number of radio communication channels among idle radio communication channels satisfying the required communication quality corresponding to the requested communication class, to that mobile station.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for wireless communication in which wireless signals of various communication types are mixed. The invention uses T
Suitable for use in DMA (Time Division Multiple Access) communication.

[0002]

2. Description of the Related Art A conventional wireless communication channel allocating method of a mobile wireless communication system covering a service area with a plurality of wireless zones allocates a plurality of wireless communication channels that can be commonly used to each wireless zone, and performs wireless communication from a mobile station. Each time a channel assignment request is made, it is checked whether or not the wireless communication channel to be assigned is being used in another wireless zone by measuring the interference wave reception level of the wireless communication channel. It is determined whether the communication quality is satisfied. If it is determined that the required communication quality is satisfied, the wireless communication channel is allocated.

When data communication is to be performed by a mobile radio communication system using TDMA, the data transmission speed can be increased by using a plurality of radio communication channels. For example, when the transmission speed per one wireless communication channel is 32 kbit / s, data communication can be performed at a transmission speed of 32 × 2 = 64 kbit / s by using two wireless communication channels.

[0004] In the conventional radio communication channel assignment method, even when there is a lot of traffic in the radio section and the received interference wave reception level is high, regardless of the interference wave reception level,
Wireless communication channel allocation is performed for a uniform and fixed number of wireless communication channels defined for each communication type (1995).
IEICE Communications Society Conference B-231
"Study of Dynamic Channel Assignment Method under Mixed Data Call / Voice Call"). For example, one wireless communication channel is assigned to voice communication, and two wireless communication channels are assigned to data communication.

[0005]

As described above, in the conventional system, a fixed radio communication channel is allocated in accordance with the communication type of the radio communication channel regardless of the state of the idle radio communication channel based on the observation result of the interference wave reception level. Number of wireless communication channels have been allocated. Therefore, if a wireless communication channel that satisfies the required communication quality cannot be searched, a call loss occurs and the connection quality deteriorates.

Further, even if the traffic is low, the reception level of the received interference wave is low, and the number of allocated radio communication channels is increased to increase the data transmission speed, a fixed number of radio communication channels are allocated. There is a problem that the communication speed cannot be increased.

SUMMARY OF THE INVENTION The present invention has been made in such a background, and it is possible to increase the frequency utilization efficiency of a wireless communication channel, reduce a call loss rate, and perform high-speed data transmission. It is an object to provide a communication channel assignment method and a wireless communication device.

[0008]

According to the present invention, a mobile station uses information on a reception level of a signal transmitted from a mobile station to a radio base station and a communication type of a radio communication channel transmitted from the mobile station to the radio base station. The present invention is characterized in that the number of assigned wireless communication channels is dynamically changed based on required communication quality for each communication type.

According to the present invention, bidirectional communication is performed between a radio base station and a mobile station via a radio line, and when a connection request is issued from the mobile station, required communication quality as a communication path is satisfied. A radio communication channel allocation method for selecting and allocating a radio communication channel to be performed, wherein when an allowable interference wave reception level is used as required communication quality, the radio base station includes:
Upon receiving a communication connection request from the mobile station, determine the communication type requested by the mobile station based on a control signal from the mobile station and measure the interference wave reception level in each wireless communication channel, and measure When the value of the interference wave reception level is less than or equal to the allowable interference wave reception level corresponding to the communication type for which the mobile station has requested a communication connection,
Radio communication channels are allocated to the communication for the number of radio communication channels equal to or less than the maximum allocated channel number corresponding to the communication type.

Here, the required communication quality may use an allowable desired wave-to-interference wave power ratio. In that case, when the wireless base station receives a communication connection request from the mobile station,
A communication type requested by the mobile station is determined based on a control signal from the mobile station, and a reception level of a control signal of a communication connection request from the mobile station is measured. A desired wave to interference wave power ratio of each wireless communication channel is calculated based on the interference wave reception level in the channel.

In the present invention, the required communication quality and the maximum number of allocated channels are set according to the type of communication such as data communication, voice, and facsimile requested by the mobile station to the radio base station. When the mobile station issues a communication connection request, the wireless base station searches for the number of wireless communication channels that satisfy the required communication quality according to the communication type of the mobile station requesting connection, and determines the number of wireless communication channels that satisfies the mobile station connection request. A wireless communication channel equal to or less than the corresponding maximum number of allocated channels is allocated to the mobile station.
As a result, the frequency use efficiency of the wireless communication channel can be improved as compared with a wireless communication channel allocation method in which the required communication quality and the number of allocated channels are fixed uniformly for each communication type. Can be reduced to at least one channel, so that the connection quality of the call can be improved, and the radio communication channels can be allocated up to the set maximum number of allocated channels. When the number is large, the data transmission speed can be increased.

In the present invention, the wireless base station searches for a wireless communication channel satisfying the required communication quality according to the communication type requested by the mobile station for connection. When there is no wireless communication channel that satisfies the required communication quality, when there is a call for performing communication using a plurality of wireless communication channels in this wireless base station, the number of wireless communication channels for this call is reduced and the number is reduced. When the wireless communication channel satisfies the required communication quality required by the mobile station requesting the connection, by assigning the wireless communication channel to the mobile station, the connection rate can be increased, and the connection quality can be improved. .

Further, by detecting interference of a wireless communication channel already allocated to the mobile station and performing communication, and allocating a new wireless communication channel for avoiding this interference, when interference occurs during communication, This can also avoid loss of information or interruption of communication.

When there is a mobile station whose communication is to be terminated,
By allocating a wireless communication channel released by the end of this communication to another mobile station that is communicating with a smaller number of wireless communication channels than the maximum number of allocated channels, the data transmission speed of this mobile station can be increased. ,
User convenience can be improved.

That is, a first aspect of the present invention is a radio communication channel allocating method, in which bidirectional communication is performed between a radio base station and a mobile station via a radio line, and a connection request is generated from the mobile station. This is a wireless communication channel allocation method in which a wireless communication channel that satisfies a required communication quality as a communication channel is selected and assigned to the mobile station. According to a feature of the present invention, the radio base station performs, based on a plurality of communication types requested by the mobile station, a radio communication channel that is equal to or less than the number of radio communication channels defined for each communication type. To be assigned to a station.

Further, the radio base station sets in advance a maximum number of allocated channels corresponding to a plurality of communication types requested by the mobile station, and selects a radio communication channel satisfying a required communication quality corresponding to the communication type. Radio communication channels equal to or less than the maximum number of allocated channels may be allocated to the mobile station.

Further, the radio base station sets in advance a maximum number of assigned channels and an allowable interference wave reception level corresponding to a plurality of communication types required by the mobile station, and receives a communication connection request from the mobile station. In this case, the communication type requested by the mobile station is determined, and the interference wave reception level in each wireless communication channel is measured. It is also possible to search for a wireless communication channel that satisfies the following condition, and to allocate, to the mobile station, a wireless communication channel equal to or less than the maximum number of allocated channels corresponding to the communication type from among the wireless communication channels.

Alternatively, two-way communication is performed between a wireless base station and a mobile station via a wireless line, and when a connection request is issued from the mobile station, a wireless communication channel that satisfies required communication quality as a communication path is selected. In the wireless communication channel allocating method to allocate to the mobile station, the wireless base station sets a maximum number of allocated channels and an allowable desired wave-to-interference power ratio corresponding to a plurality of communication types requested by the mobile station in advance, When there is a communication connection request from the mobile station, a communication type requested by the mobile station is determined based on a control signal from the mobile station, and a reception level of a control signal of the communication connection request from the mobile station is determined. Is measured, and based on the reception level of this control signal and the interference wave reception level in each wireless communication channel, the desired signal power to the interference wave power of each wireless communication channel Is calculated, a wireless communication channel that satisfies a required communication quality equal to or less than an allowable desired wave-to-interference power ratio of the communication type is searched from the respective wireless communication channels, and the search channel corresponds to the communication type. Radio communication channels equal to or less than the maximum number of allocated channels may be allocated to the mobile station.

At this time, when the wireless base station searches for a wireless communication channel to be allocated to the mobile station upon receiving a communication connection request from the mobile station, a wireless communication channel satisfying a required communication quality according to the communication type is determined. If a mobile station that is not searched and already communicates using a plurality of wireless communication channels under this wireless base station exists, the number of wireless communication channels of this mobile station is reduced, and the resulting idle When the wireless communication channel satisfies the required communication quality, it is desirable to assign this wireless communication channel to the mobile station that has requested communication connection.

Further, the radio base station detects interference of a radio communication channel already allocated to the mobile station and performing communication, and searches for a new radio communication channel for avoiding interference of the radio communication channel. When a wireless communication channel that satisfies the required communication quality according to the communication type is searched, it is preferable that the wireless communication channel be assigned to the mobile station as a new wireless communication channel for avoiding the interference.

At this time, a wireless communication channel that satisfies the required communication quality according to the communication type is not searched, and another mobile station already communicating with a plurality of wireless communication channels under the wireless base station. Is present, the number of wireless communication channels of this mobile station is reduced, and when the resulting free wireless communication channel satisfies the required communication quality, this wireless communication channel is replaced with a new wireless communication channel for avoiding interference. Is desirably assigned to the mobile station. As a result, even when interference occurs during communication, it is possible to avoid a loss of information or interruption of communication by allocating a new channel for avoiding interference.

Further, when the radio base station includes a mobile station that terminates communication and a mobile station that is communicating with a smaller number of radio communication channels than the maximum number of allocated channels, the mobile station terminates the communication. When the wireless communication channel allocated to the mobile station satisfies the required communication quality, it is preferable to additionally allocate the wireless communication channel in a range equal to or less than the maximum allocated channel number. By this means, it is possible to increase the number of allocated channels in a situation where the traffic is small and the amount of interference is small, so that it is possible to increase the data transmission rate and improve the convenience for the user.
In addition, since control is performed at the end of communication, there is no need to always search for a free wireless communication channel in the base station, so that the control method is simple, and since control is not always performed, control load is reduced. It is valid.

A second aspect of the present invention is a radio communication apparatus, which performs bidirectional communication between a radio base station and a mobile station via a radio line, and performs a communication path when a connection request is issued from the mobile station. Is a wireless communication device that selects a wireless communication channel that satisfies the required communication quality as described above and allocates it to this mobile station. The feature of the present invention is characterized in that the mobile station includes means for transmitting a request signal requesting a wireless communication channel assignment specifying a communication type to be used from among a plurality of communication types, and the wireless base station includes: Means for decoding a communication type required from the request signal, means for storing in advance a maximum number of allocated channels and required communication quality corresponding to a plurality of communication types requested by the mobile station, the decoding result and the storage information Based on, the wireless communication channels satisfying the required communication quality corresponding to the requested communication type from among the available wireless communication channels less than the maximum number of allocated channels less than the means for allocating a radio communication channel to the mobile station, Wireless communication device.

Further, the mobile station includes means for transmitting a request signal for requesting radio communication channel assignment specifying a communication type to be used from among a plurality of communication types, and the radio base station transmits the request signal from the request signal. Means for decoding the required communication type, means for storing the maximum number of allocated channels and required communication quality corresponding to the plurality of communication types requested by the mobile station in advance, based on the decoding result and the storage information, When the mobile station allocates a wireless communication channel equal to or less than the maximum allocated channel number among the available wireless communication channels satisfying the required communication quality corresponding to the requested communication type, and there is no newly available free wireless communication channel, Reduce the number of wireless communication channels of another mobile station that is already using multiple wireless communication channels, leaving at least one, Available radio communication channels Flip was can also be provided with means for assigning a wireless communication channel to a new mobile station which emits said request signal when satisfying the required communication quality.

Further, the radio base station includes means for detecting interference of a radio communication channel which has been allocated to the mobile station and is performing communication, and the allocating means performs interference avoidance according to the detection result. It is desirable to include means for allocating a new wireless communication channel satisfying the required quality to the mobile station.

At this time, if there is no free wireless communication channel to be newly assigned, the number of wireless communication channels of another mobile station already using a plurality of wireless communication channels is reduced by leaving at least one. It is preferable to include means for allocating the radio communication channel to the mobile station as a new radio communication channel for avoiding the interference when the vacant radio communication channel satisfies the required communication quality. As a result, it is possible to avoid loss of information or interruption of communication due to interference.

[0027] Further, the radio base station includes means for detecting a mobile station at which communication ends, and the allocating means comprises:
When there is a mobile station performing communication with the number of wireless communication channels smaller than the maximum allocated channel number, when the wireless communication channel assigned to the mobile station to which the communication ends in the mobile station satisfies the required communication quality, It is desirable to include means for additionally allocating a wireless communication channel in a range equal to or less than the maximum number of allocated channels. Thus, by allocating an additional free wireless communication channel to a mobile station that is already communicating, an optimal number of channels can be secured according to the communication type.

Preferably, the required communication quality is based on an interference wave reception level or a desired wave to interference wave power ratio.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an overall configuration diagram of a mobile radio communication system. FIG. 2 is a block diagram of the radio base station.

The present invention relates to a radio communication apparatus, which performs bidirectional communication between radio base stations 4 and 6 and mobile stations 5 and 7 via radio lines and generates a connection request from mobile stations 5 and 7. This is a wireless communication device that selects a wireless communication channel that satisfies the required communication quality as a communication path and assigns it to the mobile stations 5 and 7.

Here, a feature of the present invention is that the mobile stations 5 and 7 transmit a request signal for requesting wireless communication channel assignment specifying a communication type to be used from among a plurality of communication types, and The base stations 4 and 6 include a baseband signal processing unit 22 having means for decoding a communication type required from the request signal, and a maximum number of allocated channels corresponding to a plurality of communication types required by the mobile stations 5 and 7 in advance. And a storage unit 25 for storing required communication quality, based on the decryption result and the stored information, the maximum allocation from available wireless communication channels satisfying the required communication quality corresponding to the requested communication type. Processing unit 2 as means for allocating a radio communication channel equal to or less than the number of channels to the mobile station
4 is provided.

The storage unit 25 stores the maximum number of allocated channels and the required communication quality corresponding to a plurality of communication types. Further, the status of the idle wireless communication channel is stored.

Further, based on the decryption result and the stored information, the processing section 24 selects, from among the available wireless communication channels satisfying the required communication quality corresponding to the requested communication type, the number of wireless communication channels equal to or less than the maximum number of allocated channels. When channels are allocated to the mobile stations 5 and 7 and there is no free radio communication channel to be newly allocated, at least one radio communication channel of another mobile station already using a plurality of radio communication channels is left. The resulting unused wireless communication channel is newly allocated to the mobile stations 5 and 7 that issue the request signal.

The required communication quality is based on the interference wave reception level or the desired signal to interference wave power ratio. The measurement of the communication quality is performed by the determination of the processing unit 24 according to the measurement result of the interference wave reception level measured by the reception level measurement unit 23.

The processing unit 24 monitors the quality of the wireless communication channel by measuring the frame error in the wireless section detected by the baseband signal processing unit 22, and monitors the quality of the wireless communication channel based on the monitoring result. Detects that the radio communication channel is being interfered by the radio wave emitted by the radio communication channel.

[0036]

【Example】

(First Embodiment) A first embodiment of the present invention will be described. The service area 3 includes a wireless zone 1 and a wireless zone 2. The wireless zone 1 is configured by the wireless base station 4, and the wireless zone 2 is configured by the wireless base station 6. In this mobile radio communication system, there are a plurality of mobile stations, the mobile station 5 is in the radio zone 1, and the mobile station 7 is in the area of the radio zone 2. A communication path is set between the mobile station 5 and the radio base station 4, and a communication path is set between the mobile station 7 and the radio base station 6.

FIG. 2 shows the configuration of a radio base station. An antenna 20 and a transmission / reception section 21 having a modulation / demodulation function are shown in FIG.
A baseband signal processing unit 22 for generating a transmission signal, detecting and processing a reception signal, a reception level measurement unit 23 for measuring a reception level of a signal or an interference wave for each wireless communication channel, and controls the operation of the entire circuit. And a processing unit 24 for inputting a signal or interference wave reception level for each wireless communication channel of the reception level measurement unit 23, searching for an available wireless communication channel state, and calculating a desired wave to interference wave power ratio,
A storage unit 25 for storing the maximum number of allocated channels corresponding to a plurality of communication types, required communication quality, and available wireless communication channel status.

FIG. 3 is a diagram showing a call connection sequence in the first embodiment of the present invention. That is, when a call connection request is generated from the mobile station 5 or 7 to perform communication, the mobile station 5 or 7 transmits a radio communication channel assignment request signal to the radio base station 4 or 6 on a control channel. .
When the wireless base station 4 or 6 receives the wireless communication channel assignment request signal, the wireless base station 4 or 6 searches for a wireless communication channel that satisfies the required communication quality according to the wireless communication channel allocation algorithm, and searches for a wireless communication channel that satisfies the required communication quality. Then, the radio base station 4 or 6 allocates a radio communication channel to the mobile station 5 or 7 by using a radio communication channel allocation signal.

In the present invention, for example, when there is a communication connection request from the mobile station 5, the radio base station 4 determines the type of communication requested by the mobile station 5 based on a control signal from the mobile station 5. At the same time, it measures the interference wave reception level in each wireless communication channel and responds to the communication type for which the communication connection request was made from among the wireless communication channels with the allowable interference wave reception level corresponding to the communication type for which the communication connection request was made Radio communication channels are selected for the number of radio communication channels equal to or less than the maximum allocated channel number, and the radio communication channels are allocated to the mobile station 5.

At this time, not only the interference wave reception level,
Based on the reception level of the control signal of the communication connection request issued from the mobile station 5 and the interference wave reception level of each wireless communication channel, the desired wave-to-interference wave power ratio in each wireless communication channel is calculated, and there is a communication connection request. From among the wireless communication channels having an allowable desired wave-to-interference wave power ratio corresponding to the communication type or less, the number of wireless communication channels equal to or less than the maximum number of allocated channels corresponding to the communication type for which the communication connection request has been made is established. It is also possible to select and assign the wireless communication channel to the mobile station 5.

Hereinafter, a desired wave calculated from the interference wave reception level of each radio communication channel or the reception level of a control signal of a communication connection request issued from the mobile stations 5 and 7 and the interference wave reception level of each radio communication channel. The ratio of power to interference wave is defined as the quality of the wireless communication channel.

In the first embodiment of the present invention, the required communication quality value and the maximum number of allocated channels are stored in the storage unit 25 in the radio base station 4 for each communication type. FIG. 4 is a diagram showing a storage state of the required communication quality value and the maximum number of allocated channels for each communication type. The communication type A1 includes a required communication quality value C1, a maximum allocated channel number D1, and a communication type A2.
Stores the required communication quality of the wireless communication path and the maximum number of allocated channels for each communication type up to the communication type Am, such as the required communication quality value C2 and the maximum number of allocated channels D2.

Next, the operation of assigning a wireless communication channel in the first embodiment of the present invention will be described. Now, the case where the mobile station 5 requests the wireless base station 4 for a wireless communication channel will be described. When the mobile station 5 requests the wireless base station 4 to allocate a wireless communication channel, the mobile station 5 requests the wireless base station 4 to allocate a wireless communication channel on a control channel. Send a signal.

The signal is accompanied by communication type information of a wireless communication channel. The wireless base station 4 measures the reception level of the signal by the reception level measuring unit 23,
The signal is analyzed by the baseband signal processing unit 22, and the communication type of the wireless communication channel requested by the mobile station 5 is read.

FIG. 5 is a diagram showing an example of signal coding of a radio communication channel assignment request signal on a control channel.
Message type (4 bits), communication type (4 bits),
This is a signal form including a mobile station number (20 bits). FIG. 6 is a diagram showing an example of the meaning of this signal coding.
As the communication type, voice communication, data communication, FAX, and the like are set. As a result, as shown in FIG. 6A, 4 bits of the message type are changed to the bit format “0”.
If it is "001", it is understood that the signal is a communication channel assignment request signal. Further, as shown in FIG. 6B, if the subsequent 4 bits of the communication type are "0001", it is determined that the signal is voice. it can.

The processing section 24 reads out the required communication quality value for each communication type stored in advance in the storage section 25 in the radio base station 4 and corresponds to the communication type of the channel requested this time from the mobile station 5. The required communication quality value C is obtained. For example, when the requested communication type is A1, it is determined that the required communication quality value is C1. The required communication quality value here is, for example, an allowable interference wave reception level or an allowable desired wave interference wave power ratio. Hereinafter, the case where the required communication quality value is the allowable desired wave to interference wave power ratio will be described.

Assume that the communication type requested by the mobile station 5 is A1, and the reception level of the wireless communication channel assignment request signal received by the wireless base station 4 is B.

FIG. 7 shows the CIR of each wireless communication channel calculated from the interference wave reception level of each wireless communication channel measured by the wireless base station 4 and the reception level B (desired wave reception level) of the wireless communication channel assignment request signal. It is a figure which shows a mode of (desired wave to interference wave power ratio). CIR is calculated by the following equation.

CIR = (desired wave reception level B) / (interference wave reception level) This CIR is calculated for each wireless communication channel. The measurement of the interference wave reception level of each wireless communication channel may be performed when the wireless base station 4 receives a wireless communication channel assignment request from the mobile station 5 or may be continuously performed. The processing unit 24 in the wireless base station 4 calculates the CIR of each wireless communication channel (1 to n) and searches for a wireless communication channel exceeding the required communication quality value C1 of the communication type A1 previously obtained. I do. If a wireless communication channel exceeding the required communication quality value C1 is found, the wireless communication channel is stored in the storage unit 25 as an allocation candidate channel.

The processing unit 24 reads the maximum number of allocated channels for each communication type stored in the storage unit 25 in the radio base station 4 in advance, and communicates the radio communication channel requested by the mobile station 5 this time. The maximum number of allocated channels corresponding to the type is obtained (S3). For example, when the communication type of the requested wireless communication channel is A1, it is determined that the maximum number of allocated channels is D1. When the number of allocation candidate channels stored in the storage unit 25 reaches the maximum allocation channel number D1, the channel stored in the storage unit 25 as an allocation candidate channel is transmitted to the mobile station 5 that has requested a communication channel with the communication type A1. assign. Note that a wireless communication channel already used as a wireless communication channel by the wireless base station 4 is not searched.

At this time, in all radio communication channels,
When a wireless communication channel exceeding the required communication quality value C1 is not found, and when there is a mobile station communicating on a plurality of wireless communication channels in the wireless base station 4, the wireless communication of the mobile station on communication is Reduce the number of communication channels by one,
Release the wireless communication channel. It is checked whether or not the released wireless communication channel exceeds the required communication quality value C1, and if it exceeds, the wireless communication channel is allocated to the mobile station 5. If the released wireless communication channel does not exceed the required communication quality value C1, the wireless base station 4 further checks whether there is a mobile station communicating with a plurality of wireless communication channels and exists. in case of,
Similarly to the above, the number of wireless communication channels of a mobile station communicating with a plurality of wireless communication channels is reduced by one, the wireless communication channel is released, and whether the released wireless communication channel exceeds the required communication quality value C1 is determined. After confirming, if the number exceeds the number, the assignment of the wireless communication channel to the mobile station 5 is repeated in the wireless base station 4 until there is no mobile station communicating with a plurality of wireless communication channels. Even if it repeats until there are no mobile stations communicating on multiple wireless communication channels,
When the wireless base station 4 does not find a wireless communication channel exceeding the required communication quality value C1, it notifies the mobile station 5 of the fact and the call is lost.

FIGS. 8 and 9 are flow charts for explaining the above-mentioned radio communication channel allocating operation. The reception level B of the communication channel request signal transmitted from the mobile station is measured (S1). The communication type A attached to the communication channel request signal is read (S2). A required communication quality value C and a maximum allocated channel number D corresponding to the read communication type A are obtained (S3). Subsequently, the wireless communication channel number k is set to “1”. At this time, the number of allocation candidate channels stored in the storage unit 25 is “0” (S4). If the wireless communication channel number k (= 1) is not communicating (S5),
Calculate the CIR of each wireless communication channel number k (S
6). If the CIR of the wireless communication channel number k (= 1) satisfies the required communication quality C (S7), the wireless communication channel number k (= 1) is stored in the storage unit 25 as an allocation candidate wireless communication channel (S8). ). At this time, the number of allocation candidate channels stored in the storage unit 25 is “1” (S
9). If "1" is the maximum number D of allocated channels (S10), the mobile station is notified of the allocation using an allocation signal to use this communication channel k (= 1) (S1).
1).

However, if “1” is less than the maximum allocated channel number D (S10), the radio communication channel number k
Is incremented by one to “2” (S12). If this “2” is smaller than the number of system channels (S13),
Return to step 5. If “2” exceeds the number of system channels (S13), and if the number of allocation candidate channels stored in the storage unit 25 is “1” or more (S14), the mobile station moves to use the stored candidate communication channel. The station is notified by a communication channel assignment signal (S15).

If the number of allocation candidate channels stored in the storage unit 25 is "0" (S14) and there is a communication call of a plurality of radio communication channels (S16), the communication call of the plurality of communication channels Reduce the number of wireless communication channels by one,
The reduced wireless communication channel k is released (S18). The CIR of the reduced wireless communication channel k is calculated (S1
9) If the CIR exceeds the required communication quality value C (S20), the mobile station is notified by a wireless communication channel assignment signal to use the released communication channel k (S21). If the number of allocation candidate channels stored in the storage unit 25 is "0" (S14), and there is no communication call of a plurality of wireless communication channels at this time (S1).
6) The mobile station is notified that there is no wireless communication channel satisfying the required communication quality (17).

FIG. 10 is a view for explaining conditions of computer simulation for confirming the effect of the present invention. Here, as the CIR of the required communication quality value, “30 dB” is set for a data communication call and “25 dB” is set for a voice communication call.

As the maximum number of allocated channels, "4" is set for a data communication call and "1" is set for a voice communication call.

FIGS. 11 and 12 show the results of comparison between the prior art and the present invention by computer simulation. FIG. 11 shows the passing traffic (erl / cell) on the horizontal axis,
The vertical axis indicates the call loss rate. FIG. 12 shows the passing traffic (e
rl / cell), and the vertical axis shows the throughput. According to the results of computer simulation, focusing on data communication calls, the present invention has a call loss rate of 3% and
(erl / cell) (33%) It can be seen that a lot of traffic can be carried. In addition, the average throughput at this time is “2”, which indicates that the call loss rate is improved without deteriorating the average throughput as compared with the fixed system. Furthermore, at a place where the traffic is small, a throughput of “2” or more is achieved, and at a place of 5 (erl / cell), the conventional method is:
Since the wireless communication channels are allocated with a fixed number of allocated channels, the data communication throughput is “2”. However, in the example of the computer simulation of the present invention, the maximum number of allocated channels is “4”. , And a throughput of “3”, and the throughput is improved by a factor of 1.5. Naturally, if the traffic is further reduced, the throughput becomes “4”, and the effect of improving the throughput is further increased.

(Second Embodiment) FIG. 13 shows a second embodiment of the present invention.
17 will be described with reference to FIG. FIG. 13 is a flowchart for explaining the interference avoiding operation according to the second embodiment of the present invention. FIG. 14 is a flowchart showing a wireless communication channel adding operation according to the second embodiment of the present invention. FIG. 15 is a diagram showing simulation conditions for confirming the effect of the second embodiment of the present invention. FIG. 16 is a diagram showing the results of a simulation for confirming the effect of the second embodiment of the present invention, in which the horizontal axis represents passing traffic and the vertical axis represents throughput. FIG. 17 is a diagram showing the results of a simulation for confirming the effect of the second embodiment of the present invention, in which the horizontal axis represents the passing traffic and the vertical axis represents the blocking rate.

In the second embodiment of the present invention, the operation of the first embodiment of the present invention includes an interference avoiding operation when a wireless communication channel during communication is interfered and a mobile station that ends communication when there is a mobile station. An operation of additionally allocating a wireless communication channel used by a mobile station to another mobile station communicating with a smaller number of wireless communication channels than the maximum number of allocated channels is added.

When a radio communication channel used between the radio base station 4 and the mobile station 5 during communication is interfered by radio waves emitted by another radio base station or the mobile station, other radio communication channels may be used. Switching processing to a wireless communication channel that satisfies communication quality is performed. For example, the fact that the wireless communication channel under communication is receiving interference can be determined by measuring a frame error in a wireless section detected by the baseband signal processing unit 22. Now, when it is detected that the wireless base station 4 is receiving interference (S2
2) Measure the reception level B of the wireless communication channel receiving the interference (S23). In the base station 4, assuming that the communication type of the radio communication channel receiving the interference is A1,
In all wireless communication channels, wireless communication channel search processing that satisfies the required quality value C1 is performed (S24, S2).
5). When a wireless communication channel exceeding the required quality value C1 is found (S26), wireless communication channel switching processing is performed with the wireless communication channel as a wireless communication channel switching destination, and the interference avoidance processing ends (S27).

Here, if a wireless communication channel satisfying the required quality value C1 cannot be searched (S26), the call of the interfered wireless communication channel occupies a plurality of wireless communication channels. (S28) releases the wireless communication channel that is receiving the interference, and reduces the number of allocated wireless communication channels for this call by "1" (S29).

Further, when the number of occupied radio communication channels of the call of the radio communication channel receiving the interference is "1" (S28), the radio base station 4 moves the mobile station communicating with a plurality of radio communication channels. When a station exists (S3
0), the number of wireless communication channels of the communicating mobile station is reduced by “1”, and this wireless communication channel is released (S3).
2). The released wireless communication channel has a required quality value C1.
Check if it exceeds. The required quality value C1 is
IR is obtained as CIR = (desired wave reception level B) / (interference wave reception level), and it is determined whether the required quality value C1 exceeds the CIR (S33). If the required quality value C1 exceeds the CIR (S34), the wireless communication channel is allocated to the mobile station 5 (S35). This assignment
The radio base station 4 notifies the mobile station 5 with a communication channel assignment signal.

The released radio communication channel has the required quality value C
If the number does not exceed 1 (S34), the wireless base station 4 further checks whether there is a mobile station communicating with a plurality of wireless communication channels. The number of wireless communication channels of the mobile station communicating with a plurality of wireless communication channels is reduced by "1", this wireless communication channel is released, and it is confirmed whether the released wireless communication channel exceeds the required quality value C1. In this case, the assignment of the wireless communication channel to the mobile station 5 is repeated in the wireless base station 4 until there is no mobile station communicating with a plurality of wireless communication channels.

If the wireless base station 4 does not find a wireless communication channel exceeding the required quality value C1 even after repeating until there are no mobile stations communicating on a plurality of wireless communication channels, the mobile station is notified of the fact. 5 is notified (S3
1) The call is blocked because interference cannot be avoided.
FIG. 13 is a flowchart illustrating the operation when avoiding the interference of the wireless communication channel.

When the two-way communication performed between the radio base station 4 and the mobile station 5 via the radio line ends,
In the wireless base station 4, when there is a call in communication with a maximum number of allocated channels of 2 or more, the number of wireless communication channels is reduced to the maximum number of allocated channels preset for each communication type. Increase.

For example, when the communication between the radio base station 4 and the mobile station 5 is completed, the radio base station 4 performs a release process of the radio communication channel used between the mobile station 5 and
The mobile station communicating with the wireless base station 4 is searched.

Now, the number of communicating mobile stations 1 is one, the communication type of this radio communication channel is A1, and the number of occupied radio communication channels at that time is the maximum allocated channel number D
When it is smaller than 1 (≧ 2) (S36 to S41), the wireless base station 4 searches for a wireless communication channel exceeding the required quality value C1 (S42). As a result of the search, if there is a wireless communication channel that can be assigned, a wireless communication channel up to the maximum assigned channel number D1 is assigned to this mobile station (S43). To increase the number of occupied wireless communication channels. If the number of mobile stations communicating with the wireless base station 4 is plural, the operation of expanding the number of wireless communication channels is repeated for a plurality of calls (S44, S45). FIG. 14 is a flowchart illustrating the operation of additionally assigning a wireless communication channel.

FIG. 15 is a diagram showing simulation conditions for confirming the effect of the second embodiment of the present invention. Here, as a CIR of a required quality value, "3"
0 dB "," 25 dB "is set for a voice communication call, and" 4 "is set for a data communication call and" 1 "is set for a voice communication call as the maximum number of allocated radio channels.

FIG. 16 and FIG. 17 show a comparison between the conventional method and the method of the present invention by simulation. According to simulation results, when focusing on data communication calls, the method of the present invention has a call loss rate of 3% as compared with the conventional method.
It can be seen that 0.5 (erl / cell) (33%) more traffic can be carried. The average throughput at this time is "2.2", which means that the average throughput is improved as compared with the conventional method. Further, in a place where traffic is small, a throughput of “2” or more is achieved. In the conventional method, a wireless communication channel is allocated with a fixed number of allocated channels at 1.5 (erl / cell). The data communication throughput is “2”, but in the simulation example of the method of the present invention, since the maximum number of allocated wireless communication channels is “4”, the throughput “2.7” is realized, and 1.35. There is a two-fold improvement in throughput. Naturally, if the traffic is further reduced, the throughput becomes “4”, and the effect of improving the throughput is further increased.

(Summary of Embodiment) As described above, the required communication quality and the maximum number of allocated channels are set for each communication type of the wireless communication channel, and if there are many wireless communication channels satisfying the required communication quality, the maximum allocated channel When the number of wireless communication channels that satisfy the required communication quality is small, the number of allocated channels is dynamically changed according to interference conditions so that at least one wireless communication channel is allocated. In order to allocate a wireless communication channel, a system with high frequency use efficiency of a wireless communication channel can be realized. In communication in which the data transmission rate can be changed by the number of allocated channels, such as data communication, the number of radio communication channels to be allocated to the mobile station can be increased under conditions of low interference, so that the data transmission rate is increased. be able to.

When a wireless communication channel that satisfies the required communication quality is searched, and a wireless communication channel that satisfies the required communication quality cannot be searched, a wireless communication channel of a communication call communicating with a plurality of wireless communication channels is searched. By reducing the number, it is possible to allocate a wireless communication channel to an outgoing call, so that the call connection rate can be improved.

Further, when the radio communication channel switching operation is performed due to the occurrence of interference, if the radio communication channel satisfying the required quality cannot be searched in the conventional method, the connection is forcibly disconnected. According to the second embodiment, in the same radio base station, the radio communication channels of calls communicating on a plurality of radio communication channels are reduced, and this reduction is applied to a mobile station communicating on the radio communication channel that has been subject to interference. If the required wireless communication channel satisfies the required quality, by assigning it, it is possible to avoid forcible disconnection of a call that is communicating on the wireless communication channel that was receiving interference, thereby reducing the forced disconnection rate can do.

When the mobile station terminates the communication, if there is a mobile station that is communicating with the wireless base station in a number of wireless communication channels smaller than the preset maximum number of allocated channels, the communication is terminated. By allocating the radio communication channel that has been allocated to the mobile station that has finished to this mobile station, especially in a situation where the traffic is small and the amount of interference is small, the number of radio communication channels allocated to the mobile station can be increased, The data transmission speed can be increased, and user convenience can be improved. Also, since this control is performed at the end of communication, it is not necessary to always search for a free wireless communication channel in the wireless base station, so that the control method is easy.

[0074]

As described above, according to the present invention,
The frequency use efficiency of the wireless communication channel can be increased, the call loss rate can be reduced, and high-speed data transmission can be performed.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a mobile radio communication system.

FIG. 2 is a block diagram of a wireless base station.

FIG. 3 is a diagram showing a call connection sequence in a mobile radio communication system.

FIG. 4 is a diagram showing a storage state of a required communication quality value and a maximum number of allocated channels for each communication type.

FIG. 5 is a diagram showing an example of signal coding of a channel assignment request signal on a control channel.

FIG. 6 is a diagram showing an example of the meaning of signal coding.

FIG. 7 is a diagram showing a state of CIR of each channel calculated from an interference wave reception level of each channel measured by the radio base station and a reception level of a channel assignment request signal.

FIG. 8 is a flowchart illustrating a wireless communication channel assignment operation.

FIG. 9 is a flowchart illustrating a wireless communication channel assignment operation.

FIG. 10 is a view for explaining conditions of computer simulation for confirming the effect of the present invention.

FIG. 11 is a diagram showing a comparison result between a conventional technique and a method of the present invention by computer simulation.

FIG. 12 is a diagram showing a comparison result of a conventional technique and a method of the present invention by computer simulation.

FIG. 13 is a flowchart illustrating an interference avoidance operation according to the second embodiment of the present invention.

FIG. 14 is a flowchart showing a wireless communication channel adding operation according to the second embodiment of the present invention.

FIG. 15 is a diagram showing simulation conditions for confirming the effects of the second embodiment of the present invention.

FIG. 16 is a view showing the result of a simulation for confirming the effect of the second embodiment of the present invention.

FIG. 17 is a view showing the result of a simulation for confirming the effect of the second embodiment of the present invention.

[Explanation of symbols]

 1, 2 wireless zone 3 service area 4, 6 wireless base station 5, 7 mobile station 20 antenna 21 transmitting / receiving section 22 baseband signal processing section 23 reception level measuring section 24 processing section 25 storage section

Claims (14)

[Claims] 1. A bidirectional communication is performed between a radio base station and a mobile station via a radio line, and when a connection request is generated from the mobile station, a radio communication channel that satisfies required communication quality as a communication path is selected. In the wireless communication channel allocating method of allocating to the mobile station, the wireless base station, according to a plurality of communication types requested by the mobile station, has a wireless communication channel number equal to or less than the number of wireless communication channels defined for each communication type. A wireless communication channel assignment method, wherein a communication channel is assigned to the mobile station. 2. A two-way communication is performed between a wireless base station and a mobile station via a wireless line, and when a connection request is issued from the mobile station, a wireless communication channel that satisfies a required communication quality as a communication path is selected. In the wireless communication channel allocating method to allocate to the mobile station, the wireless base station sets a maximum number of allocated channels corresponding to a plurality of communication types requested by the mobile station in advance,
A wireless communication channel allocating method characterized by allocating, to the mobile station, a wireless communication channel equal to or less than the maximum number of allocated channels from among wireless communication channels satisfying required communication quality corresponding to the communication type. 3. A bi-directional communication is performed between a radio base station and a mobile station via a radio line, and when a connection request is generated from the mobile station, a radio communication channel that satisfies required communication quality as a communication path is selected. In the wireless communication channel allocating method to allocate to the mobile station, the wireless base station sets in advance a maximum number of allocated channels and an allowable interference wave reception level corresponding to a plurality of communication types requested by the mobile station, When there is a communication connection request from the station, the communication type requested by the mobile station is determined, and the interference wave reception level in each wireless communication channel is measured. A wireless communication channel that satisfies the required communication quality equal to or lower than the interference wave reception level is searched, and from the wireless communication channels, Wireless communication channel assignment method characterized by allocating the assigned channel number following the wireless communication channel to the mobile station. 4. A bidirectional communication is performed between a radio base station and a mobile station via a radio line, and when a connection request is issued from the mobile station, a radio communication channel that satisfies required communication quality as a communication path is selected. In the wireless communication channel allocating method to assign to the mobile station, the wireless base station sets in advance a maximum number of allocated channels and an allowable desired wave-to-interference power ratio corresponding to a plurality of communication types requested by the mobile station, When there is a communication connection request from the mobile station, a communication type requested by the mobile station is determined based on a control signal from the mobile station, and a reception level of a control signal of the communication connection request from the mobile station is determined. And calculates a desired signal to interference wave power ratio of each wireless communication channel based on the reception level of the control signal and the interference wave reception level of each wireless communication channel. Searching for a wireless communication channel that satisfies a required communication quality equal to or less than an allowable desired wave-to-interference power ratio of the communication type from among the wireless communication channels, and among the search channels, the maximum allocation channel corresponding to the communication type. A wireless communication channel assignment method, wherein less than or equal to a number of wireless communication channels are assigned to the mobile station. 5. The wireless base station, upon receiving a communication connection request from the mobile station and searching for a wireless communication channel to be assigned to the mobile station, searches for a wireless communication channel that satisfies required communication quality according to the communication type. However, if there is already a mobile station that communicates using a plurality of wireless communication channels under this wireless base station, the number of wireless communication channels of this mobile station is reduced, and the resulting idle wireless 5. The radio communication channel allocating method according to claim 3, wherein when the communication channel satisfies the required communication quality, the radio communication channel is allocated to the mobile station that has requested the communication connection. 6. The wireless base station detects interference of a wireless communication channel already allocated to the mobile station and performing communication, and searches for a new wireless communication channel for avoiding interference of the wireless communication channel. 5. The wireless communication system according to claim 3, wherein when a wireless communication channel satisfying a required communication quality according to the communication type is searched, the wireless communication channel is assigned to the mobile station as a new wireless communication channel for avoiding the interference. Wireless communication channel allocation method. 7. The wireless base station detects interference of a wireless communication channel already allocated to the mobile station and performing communication, and searches for a new wireless communication channel for avoiding interference of the wireless communication channel. When a wireless communication channel that satisfies the required communication quality according to the communication type is not searched, and there is another mobile station that already performs communication using a plurality of wireless communication channels under the wireless base station. The number of wireless communication channels of the mobile station is reduced, and when the resulting free wireless communication channel satisfies the required communication quality, the mobile station sets the wireless communication channel as a new wireless communication channel for avoiding the interference. 5. The wireless communication channel allocating method according to claim 3, wherein the channel is allocated to a wireless communication channel. 8. The radio base station, when there is a mobile station that terminates communication and a mobile station that is communicating with a number of radio communication channels smaller than the maximum number of allocated channels, the mobile station terminates the communication. 5. The radio communication channel allocation method according to claim 3, wherein when a radio communication channel allocated to the mobile station that satisfies the required communication quality, the radio communication channel is additionally allocated in a range equal to or less than the maximum allocated channel number. 9. A bidirectional communication is performed between a radio base station and a mobile station via a radio line, and when a connection request is issued from the mobile station, a radio communication channel that satisfies required communication quality as a communication path is selected. In the wireless communication apparatus to be assigned to the mobile station, the mobile station further comprises: means for transmitting a request signal requesting wireless communication channel assignment specifying a communication type to be used from among a plurality of communication types; Station, means for decoding the communication type requested from the request signal, means for storing in advance the maximum number of assigned channels and required communication quality corresponding to a plurality of communication types requested by the mobile station, and the decoding result Based on the stored information, radios less than the maximum number of allocated channels out of available radio communication channels satisfying the required communication quality corresponding to the requested communication type. Means for allocating a communication channel to the mobile station. 10. A bidirectional communication is performed between a radio base station and a mobile station via a radio line, and when a connection request is generated from the mobile station, a radio communication channel that satisfies a required communication quality as a communication path is selected. In the wireless communication apparatus to be assigned to the mobile station, the mobile station further comprises: means for transmitting a request signal requesting wireless communication channel assignment specifying a communication type to be used from among a plurality of communication types; Station, means for decoding the communication type requested from the request signal, means for storing in advance the maximum number of assigned channels and required communication quality corresponding to a plurality of communication types requested by the mobile station, and the decoding result Radios less than the maximum number of allocated channels out of available radio communication channels satisfying the required communication quality corresponding to the communication type requested based on the stored information When a communication channel is allocated to the mobile station, and there is no free wireless communication channel to be newly allocated, the number of wireless communication channels of another mobile station already using a plurality of wireless communication channels is reduced by leaving at least one, and Means for newly allocating the wireless communication channel to the mobile station issuing the request signal when the free wireless communication channel generated thereby satisfies the required communication quality. 11. The radio base station further comprises means for detecting interference of a radio communication channel which is already allocated to the mobile station and is performing communication, wherein the allocating means performs interference avoidance according to the detection result. The wireless communication device according to claim 9, further comprising a unit that allocates a new wireless communication channel satisfying the required quality to the mobile station. 12. The radio base station further comprises means for detecting interference of a radio communication channel which has been allocated to the mobile station and is performing communication, wherein the allocating means performs interference avoidance according to the detection result. When allocating a new wireless communication channel that satisfies the required quality, when there is no free wireless communication channel to be newly allocated, the number of wireless communication channels of another mobile station already using a plurality of wireless communication channels is reduced to at least one. Means for allocating the radio communication channel to the mobile station as a new radio communication channel for avoiding the interference when the resulting free radio communication channel satisfies the required communication quality.
Or the wireless communication device according to 10. 13. The wireless base station further comprises means for detecting a mobile station from which communication ends, wherein the allocating means includes a mobile station communicating with a wireless communication channel number smaller than the maximum allocated channel number. When the wireless communication channel allocated to the mobile station that terminates the communication to the mobile station satisfies the required communication quality, the mobile station further includes means for allocating the wireless communication channel within a range equal to or less than the maximum allocated channel number. Item 11. The wireless communication device according to item 9 or 10. 14. The radio communication apparatus according to claim 9, wherein the required communication quality is based on an allowable interference wave reception level or an allowable desired wave-to-interference wave power ratio.