JP2003289581A - Wireless communication channel allocating apparatus and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently utilize a wireless resource and increase a system capac ity, by efficiently performing channel allocation. <P>SOLUTION: When a burst type judger 104 receives a channel allocation request from a wireless communication terminal, the judger detects a transmission rate appended to the channel allocation request and required by the wireless communication terminal, judges a burst type corresponding to the transmission rate, and among a plurality of time slots contained in one frame, a channel detector 106 searches for an idle time slot not currently being used for the communication and a time slot corresponding to the burst type judged by the burst type judger 104. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication channel allocation device and a wireless communication channel allocation method.

[0002]

2. Description of the Related Art In mobile communication, multiple access such as a TDMA (Time Division Multiple Access) system or a CDMA (Code Division Multiple Access) system is provided so that a plurality of wireless communication terminal devices can simultaneously communicate in the same frequency band. The method is adopted. The TDMA method is a method of separating wireless communication channels (hereinafter, simply referred to as channels) in multiple access by using time slots obtained by temporally dividing the same frequency band. Further, the CDMA system is a system in which channels are separated in multiple access by each radio communication terminal device using different codes in the same frequency band.

On the other hand, in mobile communication, an up line (a line from a wireless communication terminal device to a wireless communication base station device) and a down line (a line from a wireless communication base station device to a wireless communication terminal device) are distinguished from each other. As a duplex system for TDD (Time Division Duplex) system and FDD (Fr
equency Division Duplex) method is adopted. T
The DD method is a method in which different time slots are used for the uplink and the downlink. Further, the FDD system is a system that uses different frequency bands for the uplink and the downlink.

In the current mobile system, the multiple access system such as the above-mentioned TDMA system and CDMA system,
It is used in combination with the duplex system such as the DD system or the FDD system. Among them, especially in the CDMA / TDD system, since the same frequency is used for the uplink and the downlink, it is possible to perform communication with a carrier wave of a single frequency. For this reason,
It has advantages such as easy application of transmission diversity,
It is expected to be used more widely in the future.

Here, in order to reduce the mutual interference between communications, the CDMA / TDD system is further added to the TD.
A communication method introducing the MA structure may be used.
In the CDMA / TDD system adopting such a TDMA structure, a plurality of data having different spreading codes are multiplexed into one time slot.

[0006]

By the way, in the CDMA / TDD system which adopts the TDMA structure, various channel allocation methods have been proposed so far, but with the increase in the number of subscribers of mobile communication in recent years, channel allocation has been performed. Is required to be done more efficiently.

The present invention has been made in view of the above points, and a wireless communication channel assigning apparatus and a wireless communication channel assigning apparatus capable of efficiently using wireless resources to improve system capacity by efficiently performing channel assignment. An object is to provide a communication channel allocation method.

[0008]

A wireless communication channel assigning device of the present invention is requested by a wireless means for performing wireless communication by a CDMA / TDD system adopting a TDMA structure with a wireless communication terminal device and the wireless communication terminal device. Determination means for determining a burst type corresponding to the transmission rate; search means for searching a time slot other than the burst type time slot different from the burst type determined by the determination means; and a search result by the search means. Based on the above, an allocating means for allocating a wireless communication channel to the wireless communication terminal device is employed.

According to this structure, since the channel search can be performed for each different burst type, the amount of processing required for the channel search can be reduced.

The radio communication channel assigning apparatus of the present invention is
Radio means for performing radio communication by a CDMA / TDD system adopting a DMA structure with a radio communication terminal apparatus, measuring means for measuring communication quality of a time slot being used by the radio communication terminal apparatus, and the measuring means. When the communication quality is equal to or lower than a predetermined value, a transmission rate determining unit that lowers the transmission rate of the wireless communication terminal device; and when the transmission rate is reduced by the transmission rate determining unit, wirelessly communicates with the wireless communication terminal device. And a allocating means for reallocating the communication channels.

According to this structure, even if the line quality is deteriorated, the forced disconnection can be avoided by decreasing the transmission rate and continuing the communication. Also, by selecting the transmission rate according to the line quality, the frequency utilization efficiency can be improved.

In the wireless communication channel allocating device of the present invention, in the above configuration, the allocating means uses the time slot selected from the time slots in use by the wireless communication terminal device, A wireless communication channel is reassigned to the.

According to this configuration, the time slot is not changed when the wireless communication channel is reallocated.
It is possible to suppress changes in the amount of interference with other cells.

In the radio communication channel allocating device of the present invention, in the above configuration, the measuring means measures the communication quality of each of a plurality of time slots being used by the radio communication terminal device, and the allocating means measures the communication quality. The wireless communication channel is reallocated to the wireless communication terminal device based on the communication quality measured by the means.

According to this structure, since the reallocation is performed based on the communication quality, the communication quality after the reallocation can be predicted to some extent.

In the wireless communication channel allocating device of the present invention, in the above configuration, the allocating means wirelessly communicates to the wireless communication terminal device by using a time slot having the best communication quality among the plurality of time slots. A configuration is used in which communication channels are reallocated.

According to this structure, when the transmission slate is lowered, the time slot having the best communication quality is selected from the plurality of time slots in use, so that the line having the good line quality is changed after the transmission rate is changed. Communication is possible.

A radio communication base station apparatus of the present invention has a configuration including any one of the above radio communication channel allocation apparatuses.

According to this structure, it is possible to provide a radio communication base station device having the same operation and effect as described above.

The radio communication terminal device of the present invention has a radio means for performing radio communication by the CDMA / TDD system adopting the TDMA structure with a radio communication base station device, and a cell list when a request for allocating a radio communication channel is rejected. And a requesting means for making a request for wireless communication channel allocation again in accordance with the priority order of 1.

According to this configuration, since the channel allocation request is made in accordance with the priority order of the cell list, the channel allocation request can be made in order from the cell having the better channel quality. Since cells with better channel quality are more likely to be granted channel allocation requests, it is possible to reduce call loss and improve system capacity by making channel allocation requests according to the priority of the cell list.

The radio communication terminal device of the present invention is rejected when a radio means for performing radio communication by the CDMA / TDD system adopting the TDMA structure with the radio communication base station device and a request for allocating the radio communication channel are rejected. And a requesting means for making a request for wireless communication channel allocation again at a transmission rate lower than the transmission rate requested by the wireless communication channel allocation request.

According to this configuration, when the wireless communication channel allocation request is rejected, the transmission rate is reduced and the channel allocation request is made again, so that the wireless communication channel allocation request is more likely to be granted. Further, call loss can be reduced and system capacity can be improved.

The radio communication channel allocation method of the present invention is
In the wireless communication by the CDMA / TDD method which adopts the DMA structure, the wireless communication channel is assigned to the wireless communication terminal device in consideration of the burst type.

According to this method, since the channel search is performed in consideration of the burst type in addition to the type of line and the use / non-use of the time slot, the amount of processing required for the channel search can be reduced.

The radio communication channel allocation method of the present invention is
In wireless communication according to the CDMA / TDD method adopting the DMA structure, a wireless communication channel is reallocated to the wireless communication terminal device by using a time slot selected from time slots in use by the wireless communication terminal device. I decided to do it.

According to this method, since the time slot is not changed when the reallocation of the wireless communication channel is performed,
It is possible to suppress changes in the amount of interference with other cells.

In the wireless communication channel allocation request method of the present invention, in the wireless communication by the CDMA / TDD method adopting the TDMA structure, when the wireless communication terminal device rejects the wireless communication channel allocation request, the cell list is prioritized. The wireless communication channel allocation request is made again according to the order.

According to this method, since the channel allocation request is made in accordance with the priority order of the cell list, the channel allocation request can be made in order from the cell having the better channel quality. Since cells with better channel quality are more likely to be granted channel allocation requests, it is possible to reduce call loss and improve system capacity by making channel allocation requests according to the priority of the cell list.

In the wireless communication channel allocation request method of the present invention, when the wireless communication terminal device rejects the wireless communication channel allocation request in the wireless communication by the CDMA / TDD system adopting the TDMA structure, the wireless communication channel is rejected. The wireless communication channel allocation request is made again at a transmission rate lower than the transmission rate requested by the communication channel allocation request.

According to this method, when the wireless communication channel allocation request is rejected, the transmission rate is reduced and the channel allocation request is made again. Therefore, the possibility that the wireless communication channel allocation request will be granted increases. Further, call loss can be reduced and system capacity can be improved.

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a table showing the correspondence between transmission rates, time slots, and burst types. Focusing on the uplink, for example, a transmission rate of 8
Burst type 1 time slots can be used at k [bps], and burst type 2 time slots can be used at a transmission rate of 144 k [bps]. As described above, in the wireless communication according to the CDMA / TDD system which adopts the TDMA structure, the transmission rate corresponds to the burst type.

FIG. 2 is a diagram for explaining the burst type. As shown in FIG. 2, each time slot includes data, a midamble (MA), and a guard period (G).
P) and. In the burst type 1 time slot, the total portion of the data and the midamble is 256 symbols. On the other hand, in the burst type 2 time slot, the total portion of the data and the midamble is 512 symbols. Also, burst type 1
The time slot midamble is shorter than the burst type 2 time slot midamble. In other words, it can be said that the burst type indicates the type of time slot structure. As shown in FIG. 1, data having a relatively low transmission rate uses burst type 1,
Burst type 2 is used for data having a relatively high transmission rate.

Here, as described above, when the burst type is different, the length of the midamble is different. Therefore,
Only the same burst type can be code-multiplexed. Referring to FIG. 1, focusing on the uplink, since 8k [bps] and 64k [bps] are both burst type 1, these data can be code-multiplexed in the same time slot. On the other hand, 8k [bp
Since [s] and 144 k [bps] have different burst types, these data cannot be code-multiplexed in the same time slot and must be transmitted using different time slots.

Therefore, the radio communication channel allocation apparatus according to the present embodiment adopts a CDMA / TDD having a TDMA structure.
In wireless communication by the method, a channel is assigned to a wireless communication terminal device in consideration of a burst type.

FIG. 3 is a block diagram showing the configuration of the radio communication channel allocation apparatus according to Embodiment 1 of the present invention.
In FIG. 3, a wireless unit 102 performs a predetermined wireless processing (down conversion, down conversion) on data transmitted from a wireless communication terminal device as a communication partner and received via an antenna 101.
A / D conversion, etc.) and input to the modulation / demodulation unit 103. Further, the data modulated by the modulation / demodulation unit 103 is subjected to predetermined wireless processing (D / A conversion, up-conversion, etc.) and transmitted from the antenna 101. Further, the radio unit 102 performs radio communication by the CDMA / TDD system adopting the TDMA structure with the radio communication terminal device under the control of the slot control unit 108. That is, the time slot designated by the slot control unit 108 is used to receive the uplink data from the wireless communication terminal apparatus and transmit the downlink data to the wireless communication terminal apparatus. At this time, different time slots are used for the uplink and the downlink. Also, a plurality of data may be code-multiplexed in one time slot.

The modulation / demodulation unit 103 performs a predetermined demodulation process on the data input from the radio unit 102. The data after the demodulation processing is obtained as received data and is input to the burst type determination unit 104. The modulation / demodulation unit 103 also performs a predetermined modulation process on the transmission data and inputs it to the wireless unit 102.

When the wireless communication terminal device requests a channel allocation, burst type determination section 104 detects the transmission rate requested by the wireless communication terminal device, which is attached to the channel allocation request. Then, the burst type corresponding to the transmission rate is determined. The table shown in FIG. 1 is stored in the storage unit 105, and the burst type determination unit 104 refers to the table shown in FIG. 1 to determine the burst type corresponding to the detected transmission rate. The channel allocation request is included in the data demodulated by the modulation / demodulation unit 103. The detected transmission rate is input to the channel allocation unit 107, and the determined burst type is input to the channel search unit 106.

The channel search unit 106 selects an empty time slot that is not currently used for communication and a time slot that matches the burst type determined by the burst type determination unit 104 from the plurality of time slots included in one frame. Search for. In other words, the burst type time slot different from the burst type determined by the burst type determination unit 104 is excluded from the search target. At this time, if it is uplink data, the time slot currently used in the uplink is searched, and if it is downlink data, the time slot currently used in the downlink is searched. As described above, since the channel search is performed in consideration of the burst type in addition to the type of the line and the use / non-use of the time slot, the amount of processing required for the channel search can be reduced. The search result is input to the channel allocation unit 107. It should be noted that the current channel allocation state is from the channel allocation unit 107 to the channel search unit 1
It is input to 06.

Here, the maximum number of codes that can be multiplexed in one time slot is predetermined. TDMA
In the wireless communication by the CDMA / TDD system which adopts the structure,
Normally, 16 times spread is equivalent to 16 times per time slot.
Codes can be multiplexed. Specifically, 1 of 8 times spread
Since the code corresponds to two 16-times spreading codes, the maximum number of 8-times spreading codes that can be multiplexed in one time slot is eight codes. Further, one code of 2 times spread corresponds to 8 codes of 16 times spread, and 1 code of 4 times spread corresponds to 4 codes of 16 times spread. Therefore, when these are multiplexed, 12 codes correspond to 16 times spread. It means that the code is multiplexed. The number of codes converted into 16 times spread is called a "resource unit". That is, TD
In the wireless communication by the CDMA / TDD system which adopts the MA structure, normally, 16 resource units can be multiplexed.

Channel allocating section 107 determines a time slot to be used for allocating a channel to the radio communication terminal apparatus which has transmitted the channel allocation request, from the time slots searched by channel searching section 106.
As described above, since the number of codes that can be multiplexed in one time slot has an upper limit, the channel allocation unit 1
07 selects a time slot with a sufficient resource unit from the time slots searched by the channel search unit 106 and allocates a channel. Specifically, the channel allocating unit 107 refers to the table (FIG. 1) stored in the storage unit 105 and sets the resource unit corresponding to the transmission rate requested by the wireless communication terminal apparatus as described above. Ask. For example, if the requested uplink transmission rate is 64 k [bps], the number of resource units is 5. Then, the calculated number of resource units is
A time slot that is less than or equal to the difference between the maximum number of resource units (that is, 16) and the current number of resource units is selected and a channel is assigned. The channel allocation result is
It is input to the slot control unit 108.

According to the channel allocation result, slot control section 108 specifies to radio section 102 the time slot used for communication with the radio communication terminal apparatus, uplink / downlink switching control, and code multiplexing number. Control of
Control for performing wireless communication by the CDMA / TDD system adopting the TDMA structure is performed.

Next, the time slot search will be described more specifically. FIG. 4 is a diagram showing an example of a frame structure. As shown in this figure, one frame is composed of 15 time slots # 0 to # 14. Here, it is assumed that time slots # 0 to # 2 are used in the common control channel, and time slots # 3 to
It is assumed that # 14 is used in the dedicated communication channel. Therefore, the time slots # 3 to # 14 can be used for channel allocation for communication with the wireless communication terminal apparatus. In the current channel allocation state, time slots # 3, # 5, # 8, and # 10 are used in the downlink, and time slots # 4, # 6, # 11, and # 12 are used in the downlink. . Also, time slots # 3, # 4, #
8, # 11 is burst type 1, time slot #
Burst type 2 is 5, # 6, # 10, and # 12.

Here, it is assumed that the wireless communication terminal device requests channel allocation of 64 k [bps] for the uplink and 384 k [bps] for the downlink. Therefore, from FIG. 1, burst type 1 is determined for the uplink,
Burst type 2 is determined for the downlink.

For the uplink, only time slots # 4, # 11 and idle time slots # 7, # 9, # 13, # 14 having the same burst type as the line are searched. Similarly, for downlinks, time slots # 5 and # with the same burst type as the line.
10, and empty time slots # 7, # 9, # 13,
Only # 14 is searched.

As described above, according to the radio communication channel allocating apparatus of this embodiment, the CDM having the TDMA structure is adopted.
In wireless communication by the A / TDD system, only the time slots that can be used for channel allocation, that is, the time slots that match the burst type and the line (uplink or downlink) are searched. Can be reduced. That is, since the channel search can be performed for each different burst type, the amount of processing required for the channel search can be reduced.
As a result, useless search can be omitted and the time required for channel allocation can be shortened.

(Embodiment 2) There is a case where the communication quality does not satisfy the desired quality for a predetermined time due to the deterioration of the transmission path condition or the like. In this case, forced disconnection is executed. However, the forced disconnection, as well as the call loss, significantly reduces the reliability of the user of the wireless communication terminal device with respect to the quality of service. Therefore, in the present embodiment, when the communication quality deteriorates, the transmission rate is temporarily reduced and the channel is reassigned to avoid the forced disconnection.

FIG. 5 is a block diagram showing the configuration of the radio communication channel allocation apparatus according to Embodiment 2 of the present invention.
In FIG. 5, the same parts as those in Embodiment 1 (FIG. 3) are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 5, the quality measuring unit 201 measures the communication quality of the data demodulated by the modulation / demodulation unit 103, that is, the communication quality of the uplink. For example, SIR (Signal
toInterference Ratio) is measured. Further, the quality measuring unit 201 extracts the downlink communication quality included in the data, which is notified from the wireless communication terminal apparatus and demodulated by the modulation / demodulation unit 103. That is, the quality measuring unit 201 measures the communication quality of the time slot being used by the wireless communication terminal device. Further, when one wireless communication terminal device is using a plurality of time slots, the quality measuring unit 201 measures the communication quality of each of the plurality of time slots. The measured communication quality is input to the transmission rate determination unit 202 and the channel allocation unit 203.

Since the radio communication channel allocation apparatus shown in FIG. 5 is used in a radio communication system of the CDMA / TDD system adopting the TDMA structure, the quality measuring unit 201 uses the measured uplink communication quality. Can also be used as the downlink communication quality. this is,
This is because, in the TDD system, if the time slot of the uplink and the time slot of the downlink are sufficiently short, the line states of them can be regarded as almost the same.

The transmission rate determining unit 202 is composed of the quality measuring unit 2
The communication quality input from 02 is compared with a predetermined value of the communication quality. When the input communication quality is equal to or lower than the predetermined value, the transmission rate is determined to be lower than the current transmission rate. When a plurality of time slots are currently used in one wireless communication terminal device, the transmission rate is lowered when the communication quality of one of the plurality of time slots becomes a predetermined value or less. Then, the reduced transmission rate is input to the channel allocation unit 203. The current transmission rate is
It is input from the channel allocation unit 203 to the transmission rate determination unit 202.

In addition to the function of the first embodiment, channel allocation section 203 reallocates channels when transmission rate determination section 202 lowers the transmission rate. At this time, the channel allocation unit 203 uses one or a plurality of time slots selected from the time slots currently used by the wireless communication terminal device that needs the channel re-allocation, and re-allocates the channel. I do. This is for the following reason.

That is, if channels are reassigned using currently used timeslots, other communication will be less affected than using timeslots not currently used, and the system can be stabilized. Because you can. That is, when reallocating channels, it is preferable not to change the channel allocation state as much as possible. Also, the time slot currently in use can be reliably used for channel reassignment. However, there is a higher possibility that the number of resource units will not be already available in the time slot that is not currently in use, compared to the time slot that is currently in use. Therefore, the wireless communication terminal device that needs to reallocate the channel reallocates the channel using a time slot selected from the time slots currently in use. As described above, according to the present embodiment, when the channel is reallocated, the time slot is not changed, so that it is possible to suppress the change in the amount of interference with other cells.

When a single radio communication terminal apparatus is currently using a plurality of time slots, the channel allocating section 203 reallocates channels using the time slot having the best communication quality. in this way,
When the transmission slate is lowered, the time slot with the best communication quality is selected from the plurality of time slots in use, so that communication can be performed via the line with the good line quality after the change of the transmission rate. Alternatively, when one wireless communication terminal apparatus is currently using a plurality of time slots, the channel allocation unit 203 reallocates channels using a time slot whose communication quality is equal to or higher than a predetermined value. At this time, the channel allocation unit 203
The predetermined value set in the above may be the same as or different from the predetermined value set in the transmission rate determining unit 202. Alternatively, the channel allocating unit 203 may determine a predetermined number and reallocate channels by using a time slot up to a predetermined number of communication qualities counted from the higher order.
In this way, since the reallocation is performed based on the communication quality, the communication quality after the reallocation can be predicted to some extent.

Next, how the channels are reallocated will be described more specifically. FIG. 6 is a diagram for explaining channel reallocation performed by the wireless communication channel assignment device according to the second embodiment of the present invention.

In FIG. 6, currently, uplink / downlink = 6
An example when data communication is performed at 4k / 384k [bps] is shown. Focusing on the downlink in FIG. 6, FIG.
Therefore, the number of resource units of the downlink 384 k [bps] is 8 and the number of time slots in use is 3 (here, three time slots # 3, # 4, and # 6). When the communication quality becomes equal to or lower than the predetermined value even in one of these three time slots, the transmission rate is lowered. Here, it is lowered from 384 k [bps] to 144 k [bps].

Since the transmission rate has been lowered, the channels are reallocated. From FIG. 1, the number of resource units of the downlink 144 k [bps] is 9, and the number of time slots used is 1. Since the number of time slots to be used is 1, the time slot having the best communication quality among the time slots # 3, # 4, and # 6 is used for channel reassignment. Here, it is assumed that time slot # 4 has the best communication quality.

Further, when the communication quality of the time slot # 4 becomes equal to or lower than the predetermined value, the transmission rate is reduced from 144k [bps] to 64k [bps]. At 144 k [bps], since only one time slot is already in use, time slot # 4 is used as it is for reassignment of channels. From FIG. 1, the number of resource units for the downlink 64 k [bps] is 5, and the number of time slots used is 1.

As described above, according to the radio communication channel allocating apparatus according to this embodiment, the CDM having the TDMA structure is adopted.
In wireless communication based on the A / TDD method, when the communication quality deteriorates, the transmission rate is temporarily reduced and channels are reassigned, so that communication can be continued and forced disconnection can be avoided. That is, even if the communication quality is deteriorated, the forced disconnection can be avoided by decreasing the transmission rate and continuing the communication. Also, by selecting the transmission rate according to the line quality, the frequency utilization efficiency can be improved. As a result, the throughput of the entire system can be improved.

(Embodiment 3) FIG.7 is a block diagram showing a configuration of a radio communication terminal apparatus according to Embodiment 3 of the present invention. In FIG. 7, radio section 302 performs predetermined radio processing (down conversion, A / D conversion, etc.) on data transmitted from a radio communication base station apparatus as a communication partner and received via antenna 301, and performs modulation / demodulation. Input to the part 303. Also, predetermined wireless processing (D / A conversion, up-conversion, etc.) on the data modulated by the modulation / demodulation unit 303.
And transmit from the antenna 301. Also, the wireless unit 3
02 is TDM under the control of the slot control unit 307.
The wireless communication by the CDMA / TDD system adopting the A structure is performed with the wireless communication base station device. That is, the slot controller 3
The time slot designated from 07 is used to receive downlink data from the radio communication base station apparatus and transmit uplink data to the radio communication base station apparatus. At this time, different time slots are used for the uplink and the downlink. Also, a plurality of data may be code-multiplexed in one time slot.

The modulation / demodulation unit 303 performs a predetermined demodulation process on the data input from the radio unit 302. The data after the demodulation processing is obtained as received data and input to the response detection unit 304. In addition, the modulation / demodulation unit 303
Performs a predetermined modulation process on the transmission data and inputs it to the wireless unit 302.

The response detection unit 304 detects a response from the radio communication channel allocation device to the channel allocation request. This response indicates whether to grant or deny the channel allocation request. A response indicating that the channel allocation request is permitted is input to slot control section 307, and a response indicating that the channel allocation request is rejected is input to request generation section 305.

The request creating section 305 creates a channel allocation request for requesting channel allocation to the wireless communication channel allocation device. A transmission rate required by the wireless communication terminal device is attached to this channel allocation request. The request creating unit 305 also stores the storage unit 306 when the wireless communication channel allocation device rejects the channel allocation request.
A channel allocation request is created again in accordance with the priority of the cell list (FIG. 8) stored in. The created channel allocation request is modulated by the modulation / demodulation unit 303, and the wireless unit 3
02 and the antenna 301 to the wireless communication base station apparatus.

When a response indicating that the channel allocation request is permitted is input from the response detection unit 304, the slot control unit 307 follows the contents of the response (transmission rate or time slot permitted to be used), CDMA having a TDMA structure such as designation of a time slot used for communication with a wireless communication base station device, control of switching between uplink and downlink, and control of the number of code multiplexes for the unit 302.
/ TDD control for wireless communication is performed.

Next, the creation of the channel allocation request will be described more specifically. FIG. 9 is a diagram showing a state of a wireless communication terminal device (MS) in a standby state and cells around it. In the following description, the wireless communication base station device (BS) arranged in each cell is the same as in the first or second embodiment.
It is assumed that the wireless communication channel allocation device according to the above is installed.

The wireless communication terminal device has a storage unit 3 shown in FIG.
In 06, a list showing the priority of connectable cells, that is, a cell list (FIG. 8) is stored. In this cell list, the higher the channel quality, the higher the priority. The cell list is created at the time of temporary connection when the power of the wireless communication terminal device is turned on.

Now, it is assumed that a communication request is made in the wireless communication terminal device. In this case, the wireless communication terminal device first creates a channel allocation request addressed to cell # 5, which has the highest priority in the cell list. When the channel allocation request is permitted in the wireless communication base station device of cell # 5 and the channel is allocated, communication is started with the wireless communication base station device of cell # 5.

On the other hand, if the channel allocation request is rejected by the radio communication base station apparatus of cell # 5 due to lack of radio resources of cell # 5 or the like, the radio communication terminal apparatus determines that cell # 5 having the next highest priority. Create a channel allocation request for 4 channels.

Thereafter, the radio communication terminal apparatus sequentially transmits channel allocation requests to the radio communication base station apparatus of each cell according to the priority of the cell list until channels are allocated. If the channel allocation request is rejected in all cells, the call is lost.

As described above, according to the radio communication terminal apparatus according to the present embodiment, the channel allocation request is made according to the priority order of the cell list, so that the channel allocation request can be made in order from the cell having the better channel quality. Since cells with better channel quality are more likely to be granted channel allocation requests, it is possible to reduce call loss and improve system capacity by making channel allocation requests according to the priority of the cell list.

(Embodiment 4) When the transmission rate required by the wireless communication terminal apparatus is relatively high, communication at that transmission rate may not be possible due to lack of wireless resources. Therefore, in the present embodiment, when the channel allocation request is rejected, the transmission rate is reduced and the channel allocation request is made again.

The wireless communication terminal apparatus according to Embodiment 4 of the present invention has the same configuration as that of Embodiment 3 (FIG. 7) and is different only in the operation of request creating unit 305. Therefore, here, request creating unit Only 305 will be described.

When the wireless communication channel allocating device rejects the channel allocation request, the request creating unit 305 creates a channel allocation request again according to the priority order of the cell list (FIG. 8) stored in the storage unit 306. To do. At this time, the request creating unit 305 makes a channel allocation request requesting a transmission rate lower than the transmission rate requested by the rejected channel allocation request.

For example, the wireless communication terminal device first makes a channel allocation request for requesting the transmission rate of the downlink 384k [bps]. At this time, it is assumed that there is not enough radio resource and there is a response from the radio communication base station device that the channel allocation request is rejected. The lower the transmission rate, the less the radio resource is used, and the higher the possibility that the channel allocation request will be granted. So at this time,
The wireless communication terminal device lowers the transmission rate from 384 k [bps] to 144 K [bps] and makes a channel allocation request again. If 144K [bps] is rejected, the transmission rate is further reduced to 64K [bps] and a channel allocation request is made. In this way, the wireless communication terminal device reduces the transmission rate and makes a channel allocation request each time the channel allocation request is rejected.

As described above, according to the radio communication terminal apparatus according to the present embodiment, when the channel allocation request is rejected, the transmission rate is reduced and the channel allocation request is made again, so that the channel allocation request is permitted. More likely,
Further, call loss can be reduced and system capacity can be improved.

The radio communication channel assigning devices according to the first and second embodiments are suitable for use in a radio communication base station device used in a mobile communication system or the like. By mounting the wireless communication channel allocation device according to Embodiments 1 and 2 in a wireless communication base station device, it is possible to provide a wireless communication base station device having the same actions and effects as above.

[0078]

As described above, according to the present invention,
By efficiently allocating channels, it is possible to efficiently use radio resources and improve the system capacity.

[Brief description of drawings]

FIG. 1 is a table showing the correspondence between transmission rates, time slots, and burst types.

FIG. 2 is a diagram for explaining a burst type.

FIG. 3 is a block diagram showing a configuration of a wireless communication channel allocation device according to the first embodiment of the present invention.

FIG. 4 is a diagram showing an example of a frame structure.

FIG. 5 is a block diagram showing a configuration of a wireless communication channel allocation device according to a second embodiment of the present invention.

FIG. 6 is a diagram for explaining channel reallocation performed by the wireless communication channel assignment device according to the second embodiment of the present invention.

FIG. 7 is a block diagram showing the configuration of a wireless communication terminal apparatus according to Embodiment 3 of the present invention.

FIG. 8: Cell list

FIG. 9 is a diagram showing a state of a wireless communication terminal device in a standby state and cells around the wireless communication terminal device;

[Explanation of symbols]

101, 301 antenna 102, 302 wireless unit 103, 303 modulator / demodulator 104 Burst type determination unit 105, 306 storage unit 106 Channel search unit 107, 203 Channel allocation unit 108, 307 Slot controller 201 Quality measurement section 202 Transmission rate determination unit 304 Response detector 305 Request creation section

Claims (12)

[Claims] 1. A wireless means for performing wireless communication by a CDMA / TDD system adopting a TDMA structure with a wireless communication terminal device, and a determining means for determining a burst type corresponding to a transmission rate requested by the wireless communication terminal device. Searching means for searching a time slot other than a burst type time slot different from the burst type judged by the judging means; and a wireless communication channel for the wireless communication terminal device based on the search result by the searching means. A wireless communication channel allocating device, comprising: 2. A radio means for performing radio communication by a CDMA / TDD system adopting a TDMA structure with a radio communication terminal apparatus, a measuring means for measuring communication quality of a time slot in use by the radio communication terminal apparatus, and the measurement. Transmission rate determining means for reducing the transmission rate of the wireless communication terminal device when the communication quality measured by the means is less than or equal to a predetermined value; and the wireless communication terminal for reducing the transmission rate by the transmission rate determining means. A wireless communication channel allocating device, comprising: allocating means for reallocating a wireless communication channel to the device. 3. The allocating means reallocates a wireless communication channel to the wireless communication terminal device using a time slot selected from time slots in use by the wireless communication terminal device. The wireless communication channel allocation device according to claim 2, wherein 4. The measuring means respectively measures the communication quality of a plurality of time slots being used by the wireless communication terminal device, and the allocating means determines the communication quality based on the communication quality measured by the measuring means. The wireless communication channel allocation device according to claim 2, wherein the wireless communication channel is reallocated to the wireless communication terminal device. 5. The allocating means reallocates a wireless communication channel to the wireless communication terminal device using a time slot having the best communication quality among the plurality of time slots. The wireless communication channel allocation device according to claim 4. 6. A wireless communication base station apparatus comprising the wireless communication channel allocation apparatus according to claim 1. Description: 7. A wireless means for performing wireless communication according to a CDMA / TDD system adopting a TDMA structure with a wireless communication base station apparatus, and when a wireless communication channel allocation request is rejected, wireless communication is performed again according to the priority of the cell list. A wireless communication terminal apparatus, comprising: requesting means for making a channel allocation request. 8. A wireless means for performing wireless communication according to a CDMA / TDD system adopting a TDMA structure with a wireless communication base station apparatus, and a rejected wireless communication channel allocation request when the wireless communication channel allocation request is rejected. And a requesting means for making a request again for assigning a wireless communication channel at a transmission rate lower than the transmission rate requested by the wireless communication terminal apparatus. 9. A wireless communication channel assigning method, wherein wireless communication channels are assigned to a wireless communication terminal device in consideration of a burst type in wireless communication according to a CDMA / TDD system adopting a TDMA structure. 10. A CDMA / TDD adopting a TDMA structure.
In wireless communication according to the method, a wireless communication channel is reallocated to the wireless communication terminal device by using a time slot selected from time slots being used by the wireless communication terminal device. Radio communication channel allocation method. 11. A CDMA / TDD adopting a TDMA structure.
In the wireless communication according to the method, when the wireless communication terminal device rejects the wireless communication channel allocation request, the wireless communication channel allocation request is again made according to the priority of the cell list. Request method. 12. A CDMA / TDD having a TDMA structure
In the wireless communication according to the method, when the wireless communication terminal device rejects the wireless communication channel allocation request, the wireless communication channel is re-established at a transmission rate lower than the transmission rate requested by the rejected wireless communication channel allocation request. A wireless communication channel allocation request method, characterized by making an allocation request.