JP2003259430A - Radio base-station equipment and method and program for slot assignment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide radio base-station equipment that can efficiently make slot assignment in the case where spatial multiplexing possible slots and spatial multiplexing restricted slots are present in a mixed state, and to provide a method and program for slot assignment. <P>SOLUTION: The channel assignment control section 14 of a spatial multiplexing base station 1000 judges whether or not a terminal requesting slot assignment is suitable for spatial multiplexing based on incoming received power, an incoming receiving timing deviation, and a terminal fading speed. The control section 14 preferentially assigns a terminal which is not suitable for spatial multiplexing to a multiplexing restricted slot and a terminal suitable for spatial multiplexing to a multiplexing possible slot based on a table of multiplexing possible slot information stored in a memory 15. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a radio base unit,
The present invention relates to a slot allocation method and a slot allocation program, and more particularly, to a radio base apparatus capable of spatially multiplex-connecting a plurality of mobile terminal apparatuses, and a slot allocation method and a slot allocation program in such a radio base apparatus.

[0002]

2. Description of the Related Art In recent years, in mobile communication systems (for example, Personal Handyphone System: PHS), which are rapidly developing, one time slot (hereinafter, slot) is provided in order to improve frequency utilization efficiency of radio waves. By performing frequency division and further spatially dividing the same frequency in the same slot, mobile radio terminal devices (terminals) of a plurality of users can be spatially (path) multiplex-connected to a radio base station (base station). Path Division Mu
ltiple access) method has been proposed.

In this PDMA system, the adaptive array technology is currently used. Adaptive array processing is to accurately extract the signal from the desired terminal by calculating and adaptively controlling the weight vector consisting of the reception coefficient (weight) for each antenna of the base station based on the received signal from the terminal. It is a process to do.

By such an adaptive array processing, the upstream signal from the antenna of each user terminal is received by the array antenna of the base station, separated and extracted with reception directivity, and transmitted from the base station to the terminal. The downlink signal is transmitted from the array antenna with transmission directivity with respect to the antenna of the terminal.

Such an adaptive array processing is a well-known technique. For example, "Adaptive Signal Processing by Array Antenna" by Nobuyoshi Kikuma (Science and Technology Publication), pages 35 to 49, "Chapter 3 MMSE Adaptive Array". Since it has been described in detail, the description of its operating principle is omitted here.

A base station to which a plurality of user terminals can be spatially multiplexed using the adaptive array technology is called a spatial multiplexing base station.

[0007]

By the way, in such a spatial multiplexing base station, ideally, it is desirable that the spatial multiplexing connection be possible in all slots.

However, in the spatial multiplexing base station,
Hardware (for example, digital signal processing device DSP) for performing digital signal processing such as adaptive array processing may be limited in its performance (for example, DSP clock speed) due to various factors such as cost.

For example, a spatial multiplexing base station constructed using an expensive DSP can be constructed so that spatial multiplexing can be performed in all slots, but a spatial multiplexing base constructed using an inexpensive DSP. In a station, slots that can be spatially multiplexed and slots that cannot be spatially multiplexed may coexist.

FIG. 6 is a diagram schematically showing a case where the slots capable of spatial multiplexing and the slots not capable of spatial multiplexing coexist as described above. In this example, it is assumed that uplink or downlink communication is performed in units of 4 slots.

First, a control channel (CCH) is assigned to one of the four slots. Spatial multiplexing is not possible in the slot to which the CCH is assigned. In the example of FIG. 6, it is assumed that CCH is assigned to slot 3.

Generally, due to hardware restrictions, CC
Spatial multiplexing of slots having a fixed relationship is limited to slots to which H is assigned. In the example of FIG. 6, CC
Spatial multiplexing is disabled in slot 2 that precedes slot 3 to which H is assigned, and spatial multiplexing is enabled in the remaining slots 1 and 4.

The limitation of such spatial multiplexing depends on various factors such as the hardware of the base station and the cost, depending on the product.
It is generated partially, and the mode thereof may vary depending on the case, and is not limited to the mode shown in FIG. 6.

On the other hand, there are some user terminals suitable for spatial multiplex connection to the base station and some terminals not suitable for the spatial multiplex connection to the base station depending on the position, the moving speed, and the like.

In the spatial multiplexing base station in which the slots capable of spatial multiplexing and the slots for which spatial multiplexing is restricted as described above are mixed, when the user terminals are terminals suitable for spatial multiplexing connection and terminals not suitable for spatial multiplexing connection, There has been a problem that it is difficult to efficiently allocate slots so that all user terminals that request connection to the base station can connect.

Therefore, an object of the present invention is to efficiently connect all user terminals that require connection, even when the slots capable of spatial multiplexing and the slots for which spatial multiplexing is limited coexist. It is an object of the present invention to provide a radio base device, a slot allocating method, and a slot allocating program capable of allocating slots well.

[0017]

According to one aspect of the present invention, a radio base apparatus to which a plurality of mobile terminal apparatuses can perform spatial multiplex connection includes a multiplexing ease determining means and a slot allocating means. . Communication with a plurality of mobile terminal devices is performed in a unit of a plurality of slots, and the plurality of slots include a slot in which spatial multiplexing is possible and a slot in which spatial multiplexing is limited. The multiplexing degree determining means determines whether or not the mobile terminal device that requires slot allocation is suitable for spatial multiplexing. The slot assigning means assigns the mobile terminal apparatus determined to be suitable for spatial multiplexing by the multiplexing ease determining means to a slot capable of spatial multiplexing, and spatially multiplexes the mobile terminal apparatus determined not to be suitable for spatial multiplexing. Are assigned to restricted slots.

[0018] Preferably, the radio base unit is based on the degree of interference level in each of the plurality of slots,
It further comprises allocation priority assigning means for assigning a normal allocation priority that is preferentially allocated from a slot having a low interference level.

Preferably, the multiplexing degree determining means determines a mobile terminal apparatus having an intermediate multiplexing degree between a mobile terminal apparatus suitable for spatial multiplexing and a mobile terminal apparatus not suitable for spatial multiplexing, and the slot allocating means determines. The mobile terminal device determined by the multiplicity determination means to have an intermediate multiplicity is assigned according to the normal assignment priority.

Preferably, the slot allocating means allocates the mobile terminal device determined to be suitable for spatial multiplexing according to the normal allocation priority order if there is no available slot for spatial multiplexing.

[0021] Preferably, the slot allocation means allocates the mobile terminal device determined not to be suitable for spatial multiplexing in accordance with the normal allocation priority order if there is no vacant slot for which spatial multiplexing is restricted.

Preferably, the multiplexing ease determination means determines the multiplexing ease when the allocation priority assigning means gives the normal allocation priority to two or more slots.

Preferably, the multiplicity determination means determines the multiplicity on the basis of the received power level from the mobile terminal device that requires slot allocation.

Preferably, the multiplicity determination means determines the multiplicity based on the reception timing from the mobile terminal device that requires slot allocation.

Preferably, the multiplexing degree determining means determines the multiplexing degree based on the moving speed of the mobile terminal device requesting the slot allocation.

[0026] According to another aspect of the present invention, there is provided a slot allocation method in a radio base apparatus capable of spatially multiplex-connecting a plurality of mobile terminal apparatuses, wherein communication with the plurality of mobile terminal apparatuses is performed in a unit of a plurality of slots. The plurality of slots include a slot in which spatial multiplexing is possible and a slot in which spatial multiplexing is limited. The slot allocation method includes a step of determining whether or not a mobile terminal apparatus that requires slot allocation is suitable for spatial multiplexing, and a slot capable of spatially multiplexing the mobile terminal apparatus determined to be suitable for spatial multiplexing. And allocating the mobile terminal device determined to be not suitable for spatial multiplexing to the slot for which spatial multiplexing is restricted.

[0027] Preferably, the slot allocation method further comprises the step of assigning a normal allocation priority in which slots having lower interference levels are preferentially allocated based on the degree of interference level in each of the plurality of slots.

[0028] Preferably, the step of determining whether or not suitable for spatial multiplexing is a mobile terminal device having an intermediate multiplexing degree between a mobile terminal device suitable for spatial multiplexing and a mobile terminal device not suitable for spatial multiplexing. The step of determining and including the step of allocating the slot includes the step of allocating the mobile terminal device determined to have the intermediate multiplicity according to the normal allocation priority.

Preferably, in the step of allocating slots, the mobile terminal device determined to be suitable for spatial multiplexing is allocated according to the normal allocation priority order if there are no available slots for spatial multiplexing.

Preferably, in the step of allocating slots, if the mobile terminal device determined not to be suitable for spatial multiplexing is free in a slot for which spatial multiplexing is restricted,
Allocation according to the normal allocation priority.

Preferably, in the step of determining whether or not it is suitable for spatial multiplexing, the degree of multiplexing is determined when the normal allocation priority is given to two or more slots.

Preferably, in the step of determining whether or not it is suitable for spatial multiplexing, the degree of multiplexing is determined based on the received power level from the mobile terminal device that requires slot allocation.

Preferably, in the step of determining whether or not it is suitable for spatial multiplexing, the degree of multiplexing is determined based on the reception timing from the mobile terminal device that requires slot allocation.

Preferably, in the step of determining whether or not it is suitable for spatial multiplexing, the degree of multiplexing is determined based on the moving speed of the mobile terminal device requesting slot allocation.

According to still another aspect of the present invention, there is provided a slot allocation program in a radio base device capable of spatially multiplex-connecting a plurality of mobile terminal devices, wherein the communication with the plurality of mobile terminal devices is performed by a plurality of slots. It is carried out in units, and the plurality of slots are slots capable of spatial multiplexing,
And slots for which spatial multiplexing is limited. The slot allocation program causes the computer to determine whether or not the mobile terminal device that requires slot allocation is suitable for spatial multiplexing, and the mobile terminal device that is spatially multiplexed for the mobile terminal device determined to be suitable for spatial multiplexing. Assigning to a possible slot and allocating the mobile terminal device determined to be not suitable for spatial multiplexing to the slot for which spatial multiplexing is limited.

Preferably, the slot allocation program is
Based on the degree of interference level in each of the plurality of slots, the computer is further caused to perform a step of assigning a normal allocation priority in which slots having lower interference levels are preferentially allocated.

[0037] Preferably, the step of determining whether or not it is suitable for spatial multiplexing uses a mobile terminal device having an intermediate multiplexing degree between a mobile terminal device suitable for spatial multiplexing and a mobile terminal device not suitable for spatial multiplexing. The step of determining and including the step of allocating the slot includes the step of allocating the mobile terminal device determined to have the intermediate multiplicity according to the normal allocation priority.

[0038] Preferably, in the step of allocating slots, the mobile terminal device determined to be suitable for spatial multiplexing is allocated according to the normal allocation priority order if there are no available slots for spatial multiplexing.

Preferably, in the step of allocating slots, if the mobile terminal device determined not to be suitable for spatial multiplexing is free in a slot where spatial multiplexing is restricted,
Allocation according to the normal allocation priority.

Preferably, in the step of determining whether or not it is suitable for spatial multiplexing, the degree of multiplexing is determined when the normal allocation priority is given to two or more slots.

Preferably, in the step of determining whether or not it is suitable for spatial multiplexing, the degree of multiplexing is determined based on the received power level from the mobile terminal device that requires slot allocation.

Preferably, in the step of determining whether or not it is suitable for spatial multiplexing, the degree of multiplexing is determined based on the reception timing from the mobile terminal device that requires slot allocation.

Preferably, in the step of determining whether or not it is suitable for spatial multiplexing, the degree of multiplexing is determined based on the moving speed of the mobile terminal device requesting slot allocation.

Therefore, according to the present invention, a slot that can be spatially multiplexed or a slot in which spatial multiplexing is limited to the mobile terminal apparatus is required depending on whether or not the mobile terminal apparatus that requires slot allocation is suitable for spatial multiplexing. Since it is configured so that all the mobile terminal devices requesting the slot allocation can be connected, it is possible to realize efficient slot allocation.

[0045]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail with reference to the drawings. It should be noted that the same or corresponding parts in the drawings are designated by the same reference numerals and description thereof will not be repeated.

First, the principle of the present invention will be described.
As described above, the user terminals include terminals that are (easy) suitable for spatial multiplex connection and terminals that are not (not easy) suitable for spatial multiplex connection.

FIG. 1 is a diagram for schematically explaining the spatial multiplexing ease for each user terminal.

Referring to FIG. 1, spatial multiplexing base station 1 communicates with user terminals 3 to 6 in area 2. Here, the uplink reception power level at the base station 1 from the terminal 3 located at the end of the area 2 is low and is not suitable for multiple connection with other user terminals in the same slot.

This is because, in a base station that allows such spatial multiplex connection, the power ratio (Desired user's power: De
This is because it is desirable that sired user's power (hereinafter referred to as DD ratio) be aligned with each other.

This is because if there is a large difference in the received power from a plurality of user terminals, the interference removal capability of the adaptive array processing will not be reached, and the received signal with the lower received power will be regarded as a reception error. This is because there is a possibility that it will end up. It is unlikely that another user having the same uplink received power exists at the edge of the area like terminal 3, and therefore terminal 3 is not suitable for multiple connection with other users (hard to multiplex).

On the other hand, referring to FIG. 1, the uplink reception power level at base station 1 from terminal 4 close to base station 1 is high, and another user exists in a narrow area close to base station 1. Possibility is low. Therefore, for the above reason, this terminal 4 is also not suitable for multiple connection with many user terminals in the same slot.

The other user terminals 5 and 6 are considered to be the user terminals in the areas where the users are most distributed, and the upstream reception power levels from these terminals in the base station 1 are almost intermediate values. It is considered to be suitable for multiple connection between user terminals.

In such a situation, for example, if a user terminal that is not suitable for spatial multiplexing is assigned to a slot that can be spatially multiplexed, another user terminal can no longer be assigned to that slot, and the efficiency of allocation is increased. Will be significantly impaired.

As described above, in the conventional spatial multiplexing base station,
Since slots that can be spatially multiplexed and slots in which spatial multiplexing is limited are mixed, efficient slot allocation is difficult. However, in the present invention, a user terminal requesting a connection is suitable for spatial multiplexing. The present invention aims to realize efficient slot allocation by allocating slots that can be spatially multiplexed or slots for which spatial multiplexing is limited, depending on whether or not they exist.

More specifically, according to the present invention, if there is a connection (slot allocation) request from a user terminal suitable for spatial multiplexing, that is, a user terminal that can easily perform spatial multiplexing, this terminal can be spatially multiplexed. Prioritize allocation to slots.
On the other hand, if there is a connection request from a user terminal that is not suitable for spatial multiplexing, that is, a user terminal that is not easy to spatially multiplex, this terminal is preferentially assigned to a slot in which spatial multiplexing is restricted (non-multiplexable).

That is, when a terminal that is not easily spatially multiplexed requests slot allocation, if a slot that can be spatially multiplexed is allocated, as for the slot, a user who later requests connection will request the slot. You will no longer have the opportunity to make multiple connections. Therefore, in the present invention, if there is a slot allocation request from a terminal for which spatial multiplexing is not easy, by allocating this terminal preferentially to a slot for which spatial multiplexing is restricted, it is easy to perform spatial multiplexing that has requested slot allocation later It is configured to control slot allocation so that as many user terminals as possible can be allocated to spatially-multiplexable slots.

In the above explanation of the principle, the uplink received power from the terminal requesting the connection is used as a factor for judging the ease of spatial multiplex connection of the terminal, but this is not limited to the uplink received power. Instead, it is possible to use various judgment factors such as the amount of deviation of the uplink reception timing from the expected reception timing position (synchronization position) in the slot of the terminal, the fading speed indicating the moving speed of the terminal, and the like. Further, these plural kinds of judgment elements may be combined appropriately and used for the judgment of the ease of multiplexing.

FIG. 2 is a schematic block diagram showing the configuration of spatial multiplexing base station 1000 according to the embodiment of the present invention.

Referring to FIG. 2, spatial multiplexing base station 1000
Is a plurality of antennas, for example, n antennas A1,
An array antenna composed of A2, ..., An is provided. The antennas A1, A2, ..., An are connected to the received signal combiner 10.

The received signal supplied to the received signal synthesizing section 10 is subjected to various kinds of analog signal processing such as amplification and frequency conversion, then converted into a digital signal and subjected to digital signal processing.

More specifically, the received signal synthesizing section 10 separates and extracts the signals from each user terminal by the well-known adaptive array processing described above, and outputs them as received signals. The received signal output is given to a modem (not shown).

The spatial multiplexing base station 1000 further includes a reception power measuring unit 11, a reception timing measuring unit 12, a fading speed measuring unit 13, a channel allocation control unit 14,
And a memory 15.

The received power measuring section 11 includes antennas A1 and A
2, ..., An from each of the received signals, RSSI, which is the instantaneous value of the received power level of the user terminal requesting the connection (slot allocation), is measured and given to the channel allocation control unit 14.

The reception timing measuring section 12 measures the reception timing of the user terminal requesting the connection from the reception signal given from the reception signal synthesizing section 10 by using the well-known correlation synchronization method or the like, and receives it as the reception timing information. It is given to the signal synthesis unit 10 and the channel allocation control unit 14.

That is, normally, in order to facilitate the separation of a plurality of users who are multiple-connected to one slot, the reception timing positions of the multiple users are set so that the reception timing positions (synchronization positions) in the slots are sufficiently separated from each other. is expected. The reception timing unit 12 calculates the deviation between the reception timing of the user terminal requesting the connection and the expected reception timing to generate the reception timing information.

The fading speed measuring unit 13 measures the fading speed of the user terminal requesting the connection from the received signal supplied from the received signal combining unit 10, and supplies it to the channel allocation control unit 14.

The propagation environment of the propagation path from the user terminal is represented, for example, by the fluctuation of the reception coefficient of the propagation path, that is, the fading speed. The fading speed is represented by a so-called Doppler frequency (fD) as a physical quantity.

The Doppler frequency fD in the propagation environment is estimated as follows, for example. That is, the correlation value of two reception response vectors temporally before and after the reception signal of the user extracted by the adaptive array processing is calculated. If there is no fading, the two reception response vectors match and the correlation value is 1. On the other hand, if the fading is severe, the difference between the reception response vectors becomes large and the correlation value becomes small. The relationship between the correlation value of the reception response vector and the Doppler frequency fD is experimentally obtained in advance,
If the table is stored in the memory, the Doppler frequency fD at that time can be estimated by calculating the correlation value of the reception response vector.

The channel allocation control unit 14 uses the RSSI measured by the reception power measuring unit 11, the reception timing information measured by the reception timing measuring unit 12, and the Doppler frequency fD measured by the fading speed measuring unit 13. Based on this, the slot allocation control according to the present invention is executed with reference to the later-described multiplexable slot information table held in the memory 15.

The processes of the received signal synthesizing unit 10, the received power measuring unit 11, the receiving timing measuring unit 12, the fading speed measuring unit 13, and the channel allocation control unit 14 shown in FIG. 2 are actually the DSP of the base station. It is realized by software using.

Next, FIG. 3 is a diagram showing an example of a multiplexing possible slot information table stored in the memory 15 of the spatial multiplexing base station 1000 shown in FIG.

This multiplexing available slot information table shows the slots that can be spatially multiplexed and the slots that cannot be spatially multiplexed, which are determined by the slot (CCH number) in which the CCH enters in the spatial multiplexing base station 1000.

Referring to FIG. 3, when CCH is assigned to slot 1, slots 2, 3 and 4 are all spatially multiplexable slots. Then C in slot 2
Slots 1, 3 and 4 if CH is assigned
Are all slots that can be spatially multiplexed. Next, when the CCH is assigned to slot 3, slots 2 and 4 are spatially multiplexed slots, but slot 1 is a spatially non-multiplexable slot. Finally, CCH in slot 4
Is assigned, slots 1 and 3 are spatially multiplexable slots, while slot 2 is a spatially non-multiplexable slot.

The channel allocation control unit 14 of FIG. 2 refers to the table of FIG. 3 to identify the slots that can be spatially multiplexed and the slots that cannot be spatially multiplexed from the slots (CCH numbers) to which CCHs are actually allocated. However, it is used for the slot allocation processing described later.

FIG. 4 is a flow chart showing the slot allocation processing according to the embodiment of the present invention, which is executed by the DSP (not shown) of spatial multiplexing base station 1000 of FIG.

In the processing of the embodiments described below, as factors for determining the degree of multiplexing of the user terminal, the uplink received signal level (RSSI), the deviation of the uplink received timing,
Although the fading speed (Doppler frequency fD) of the terminal is used in combination, the present invention is not limited to such combination, and any element that can determine the spatial multiplexing ease of the user terminal can be used. Any element can be used alone or in combination.

Referring to FIG. 4, first, in step S1, the slot selection operation is started. Such a slot selection operation is activated, for example, when the following event occurs.

For example, when a certain user terminal newly makes a call to the base station (requests a link channel), slot selection is activated. It is also activated when a channel switch (TCH switch) from another slot of the base station is requested for some reason.

Further, even in the normal communication state with the terminal after the slot is once allocated, the base station is in a communication state (for example, uplink reception power, deviation of uplink reception timing,
Fading speed, etc.) is constantly monitored, and slot selection is activated when the status changes.

For example, when a user terminal that is located far away and is not suitable for spatial multiplexing approaches a base station and changes to a terminal suitable for spatial multiplexing, slot selection is activated to change from a non-multiplexable slot to a multiplexable slot. Change the allocation to On the other hand, when a user terminal that was suitable for spatial multiplexing moves to a distant location and changes to a terminal that is not suitable for spatial multiplexing, the slot selection is activated to change the allocation from the muxable slots to non-muxable slots. To do.

In these cases, slot selection is started in step S1, and then in step S2, slot prioritization by normal slot selection is executed.

In this step, slots 1 to 4
In each of the above, the level of the interference wave is measured, and the terminal is not assigned to the slot in which the level of the interference wave exceeds the threshold value. Then, among the slots that do not exceed the threshold value, the allocation priority is given in order from the lowest interference wave level. As a result, if there are two or more slots that are the targets of slot allocation, the process proceeds to step S3, and the slot allocation is determined by determining the ease of multiplexing of user terminals, as described below.

If there is no slot to be slot-allocated, slot allocation is prohibited, and if there is only one slot,
The terminal is assigned to the slot without performing the following determination process.

In step S3, it is determined whether the user terminal is not suitable for spatial multiplexing based on the uplink reception power (RSSI) of the user terminal for which slot allocation is requested, the deviation of the uplink reception timing, and the fading speed. Make a decision.

In this example, the user terminal which is not suitable for spatial multiplexing (is not easy to multiplex) is, as described above with reference to FIG. 1, the uplink received power RSSI from the terminal.
Is too large (for example, larger than 55 dB) or too small (for example, smaller than 20 dB).

Alternatively, from the viewpoint of upstream reception timing, a terminal that is not suitable for spatial multiplexing is a terminal whose reception timing of the user deviates greatly from the expected reception timing (for example, one symbol or more).

Alternatively, from the viewpoint of fading speed,
A terminal that is not suitable for spatial multiplexing is a terminal whose fading speed (moving speed) of the user is too high (for example, Doppler frequency fD is higher than 60 Hz).

Therefore, in step S3, if the terminal requesting the slot allocation satisfies any one of the above-mentioned conditions regarding the RSSI, the reception timing deviation, and the Doppler frequency fD, the terminal is
If it is determined that the terminal is not suitable for spatial multiplexing, step S
Go to 4.

In this step S4, if there is a vacant slot in which spatial multiplexing is restricted, the terminal is preferentially assigned to the slot, and if there is no vacant slot, the step S4 is performed.
Based on the normal priority determined in 2, the slots are assigned to multiplexable slots.

On the other hand, if all the conditions in step S3 are not satisfied, the slot is determined not to be a terminal not suitable for spatial multiplexing, and the process proceeds to step S5.

In this step S5, if there is a vacant space in the spatially multiplexable slots, the relevant terminal is preferentially assigned to the slot. Are assigned to restricted slots.

In the slot allocation according to the embodiment of FIG. 4, since the user terminal which is not suitable for the spatial multiplexing is controlled to be preferentially allocated to the multiplexing limited slot, the spatial multiplexing possible slot is suitable for the spatial multiplexing. It can be reserved for a user terminal that has already been used, and efficient slot allocation can be performed.

By the way, the condition shown in step S3 of FIG. 4 is a condition for judging a terminal that is not suitable for spatial multiplexing, and strictly speaking, all terminals that do not satisfy this condition are suitable for spatial multiplexing. It cannot always be said that it is a terminal.

That is, in order to strictly determine that the terminal is suitable for spatial multiplexing (easy to multiplex), not only the condition of step S is not satisfied, but also the condition is weighted. FIG. 5 is a flow chart showing another example of the slot allocation processing to which such a condition is further imposed.

Steps S11 to 14 of the processing shown in FIG.
Is the same as steps S1 to S4 of the processing of FIG.

In step S13 of FIG. 5, when the user terminal requesting the connection does not satisfy any of the reception power RSSI, the reception timing deviation, and the fading speed defined in step S13, that is, spatial multiplexing is performed. If it is determined that the terminal is not an unsuitable terminal, the process proceeds to step S15, and it is determined whether or not the terminal is truly suitable for spatial multiplexing (easy to multiplex).

In this example, a user terminal truly suitable for spatial multiplexing (easy to multiplex) means that the uplink received power RSSI from the terminal is too large, as described above with reference to FIG. It is not too small and is not too small, and is within a certain appropriate range (for example, 35 dB to 45 dB). At the same time, when viewed from the upstream reception timing, the reception timing of the user is
In the immediate vicinity of the expected reception timing (for example, 0.5
At the same time, the fading speed (moving speed) of the user is small when viewed from the fading speed (for example, the Doppler frequency fD is 40H).
terminals smaller than z).

Therefore, in step S15, if the terminal requesting the slot allocation satisfies all the above-mentioned conditions regarding the RSSI, the reception timing shift, and the Doppler frequency fD, the terminal strictly performs spatial multiplexing. It is determined that the terminal is suitable for, and the process proceeds to step S16.

In this step S16, if there is a free space in the space-multiplexable slots, the relevant terminal is preferentially assigned to the slot. If there is no free space, multiplexing is performed based on the normal priority order determined in step S12. Are assigned to restricted slots.

[0100] The condition 1 regarding the RSSI, the reception timing shift, and the Doppler frequency fD in step S15
If none of them is satisfied, it is determined that the user terminal is a terminal in a gray zone intermediate between terminals suitable for spatial multiplexing and terminals not suitable for spatial multiplexing, and the process proceeds to step S17.

In step S17, slots are assigned to the user based on the normal priority order determined in step S12.

In the slot allocation according to the embodiment of FIG. 5, user terminals that are not suitable for spatial multiplexing are preferentially allocated to the multiplex limiting slots, and user terminals that are suitable for spatial multiplexing are preferentially allocated to the muxable slots. Therefore, it is possible to effectively allocate the space-multiplexable slots to the user terminals suitable for space-multiplexing,
Efficient slot allocation can be performed.

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[0104]

As described above, according to the present invention, depending on whether or not the user terminal requesting the connection is suitable for spatial multiplexing, the slots or spatial multiplexing capable of spatial multiplexing are limited to the user terminal. Since it is configured to allocate the slots to be allocated, it is possible to realize an efficient slot allocation in which all the users requesting the connection can connect.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a distribution state of user terminals in an area of a spatial multiplexing base station.

FIG. 2 is a functional block diagram showing a configuration of a spatial multiplexing base station according to the embodiment of the present invention.

FIG. 3 is a diagram showing a multiplexable slot information table of the spatial multiplexing base station according to the embodiment of the present invention.

FIG. 4 is a flowchart showing slot allocation control according to the embodiment of the present invention.

FIG. 5 is a flowchart showing another example of slot allocation control according to the embodiment of the present invention.

FIG. 6 is a schematic diagram showing an aspect in which spatially multiplexable slots and spatially non-multiplexable slots are mixed.

[Explanation of symbols]

1 spatial multiplexing base station, 2 areas, 3, 4, 5, 6 user terminals, 10 reception signal combining section, 11 reception power measuring section, 12 reception timing measuring section, 13 fading speed measuring section, 14 channel allocation control section, 15 Memory, A1, A2, ..., An antenna.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Naoki Ando             1-1 Sanyo-cho, Daito-shi, Osaka Sanyo Teleco             Communications Co., Ltd. (72) Inventor Yoshiharu Doi             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. (72) Inventor Shogo Nakao             2-5-3 Keihan Hondori, Moriguchi City, Osaka Prefecture             Within Yo Denki Co., Ltd. F term (reference) 5K067 AA03 AA13 BB04 BB08 CC02                       CC05 DD34 EE02 EE10 EE63                       EE65 EE71 JJ02 JJ12 JJ43                       KK01 KK13

Claims (27)

[Claims] 1. A radio base apparatus capable of spatially multiplex-connecting a plurality of mobile terminal apparatuses, wherein communication with the plurality of mobile terminal apparatuses is performed in units of a plurality of slots. A multiplexing ease determination means for determining whether or not a mobile terminal device that requires slot allocation is suitable for spatial multiplexing, including slots capable of multiplexing and slots for which spatial multiplexing is restricted; The mobile terminal device determined to be suitable for spatial multiplexing by the degree determining means is assigned to the slot capable of spatial multiplexing, and the mobile terminal device determined to be not suitable for spatial multiplexing is slot limited to the spatial multiplexing. And a slot allocating means for allocating to the radio base station. 2. The assignment priority assigning means for assigning a normal assignment priority, which is preferentially assigned from a slot having a low interference level, based on the degree of the interference level in each of the plurality of slots. The wireless base device described. 3. The multiplexing easiness determination unit determines a mobile terminal device having an intermediate multiplexing easiness between a mobile terminal device suitable for spatial multiplexing and a mobile terminal device not suitable for spatial multiplexing, and the slot allocation unit. 3. The mobile terminal device, which has been determined to have an intermediate multiplicity by the multiplicity determination means, is assigned in accordance with the normal assignment priority order.
The radio base unit according to. 4. The slot allocating means allocates the mobile terminal device determined to be suitable for the spatial multiplexing according to the normal allocation priority order if there is no vacant slot for the spatial multiplexing. The radio base unit according to 2 or 3. 5. The slot allocating means allocates a mobile terminal device determined not to be suitable for the spatial multiplexing in accordance with the normal allocation priority order if there is no vacant slot in which the spatial multiplexing is restricted. The radio base unit according to Item 2 or 3. 6. The multiplexing ease determination means determines the multiplexing ease when the normal allocation priority is assigned to two or more slots by the allocation priority assigning means. The radio base unit according to any one of 1. 7. The ease-of-multiplex determination unit makes the determination of the degree-of-multiplex based on a received power level from a mobile terminal device that requires allocation of the slot. Wireless base station. 8. The ease-of-multiplex determination means according to claim 1, wherein the ease-of-multiplex determination unit determines the degree of multiplexing based on a reception timing from a mobile terminal device that requires allocation of the slot. Radio base unit. 9. The radio base station according to claim 1, wherein the multiplexing ease determination means determines the multiplexing ease based on the moving speed of the mobile terminal device requesting the slot allocation. apparatus. 10. A method for allocating a slot in a radio base apparatus capable of spatially multiplex-connecting a plurality of mobile terminal apparatuses, wherein communication with the plurality of mobile terminal apparatuses is performed in a unit of a plurality of slots. The slot includes a slot that can be spatially multiplexed and a slot for which spatial multiplexing is limited. A step of determining whether or not a mobile terminal device that requires slot allocation is suitable for spatial multiplexing, and Assigning a mobile terminal device determined to be suitable to the slot capable of spatial multiplexing, and assigning a mobile terminal device determined not to be suitable to spatial multiplexing to a slot to which the spatial multiplexing is limited, Slot allocation method. 11. The slot allocation according to claim 10, further comprising the step of assigning a normal allocation priority that is preferentially allocated from a slot having a low interference level, based on the degree of the interference level in each of the plurality of slots. Method. 12. The step of determining whether or not it is suitable for spatial multiplexing includes a mobile terminal apparatus having an intermediate multiplexing degree between a mobile terminal apparatus suitable for spatial multiplexing and a mobile terminal apparatus not suitable for spatial multiplexing. 12. The step of determining, wherein the step of allocating the slot includes the step of allocating the mobile terminal device determined to have the intermediate multiplicity according to the normal allocation priority.
Slot allocation method described in. 13. The step of allocating the slots comprises:
If the mobile terminal device determined to be suitable for the spatial multiplexing is free in a slot capable of the spatial multiplexing,
The slot allocation method according to claim 11 or 12, wherein allocation is performed according to the normal allocation priority order. 14. The step of allocating said slots comprises:
The mobile terminal device determined not to be suitable for the spatial multiplexing is allocated according to the normal allocation priority order if there is no available slot for which the spatial multiplexing is limited.
13. The slot allocation method described in 1 or 12. 15. The method according to claim 11, wherein the step of determining whether or not it is suitable for the spatial multiplexing determines the degree of multiplexing when the normal allocation priority is assigned to two or more slots. 15. The slot allocation method according to any one of 14. 16. The step of determining whether or not it is suitable for the spatial multiplexing determines the degree of multiplexing based on the received power level from the mobile terminal apparatus that requires the slot allocation. 16. The slot allocation method according to any one of 1 to 15. 17. The method according to claim 10, wherein the step of determining whether or not it is suitable for the spatial multiplexing determines the degree of multiplexing based on the reception timing from the mobile terminal apparatus that requires the slot allocation. 16. The slot allocation method according to any one of 15. 18. The method according to claim 10, wherein in the step of determining whether or not it is suitable for spatial multiplexing, the degree of multiplexing is determined based on the moving speed of the mobile terminal device requesting the slot allocation. A slot allocation method according to any one of the above. 19. A slot allocation program in a radio base apparatus capable of spatially multiplex-connecting a plurality of mobile terminal apparatuses, wherein communication with the plurality of mobile terminal apparatuses is performed in units of a plurality of slots. The slots are
A step of determining whether or not a mobile terminal device that requires allocation of slots is suitable for spatial multiplexing, including slots capable of spatial multiplexing and slots for which spatial multiplexing is restricted; Assigning a mobile terminal device determined to be suitable to the slot capable of spatial multiplexing, and assigning a mobile terminal device determined not to be suitable to spatial multiplexing to a slot to which the spatial multiplexing is restricted. , Slot allocation program. 20. Based on the degree of interference level in each of the plurality of slots, further causing the computer to execute a step of assigning a normal allocation priority in which slots having lower interference levels are preferentially allocated.
9. The slot allocation program according to item 9. 21. The step of determining whether or not it is suitable for spatial multiplexing includes a mobile terminal apparatus having an intermediate multiplexing degree between a mobile terminal apparatus suitable for spatial multiplexing and a mobile terminal apparatus not suitable for spatial multiplexing. 21. A step of determining, wherein the step of allocating the slot includes the step of allocating the mobile terminal device determined to have the intermediate multiplicity according to the normal allocation priority.
The slot allocation program described in. 22. The step of allocating said slots comprises:
If the mobile terminal device determined to be suitable for the spatial multiplexing is free in a slot capable of the spatial multiplexing,
The slot allocation program according to claim 20 or 21, wherein the slot allocation program allocates according to the normal allocation priority order. 23. The step of allocating said slots comprises:
The mobile terminal device determined not to be suitable for the spatial multiplexing is allocated according to the normal allocation priority order if there is no vacant slot for which the spatial multiplexing is restricted.
The slot allocation program described in 0 or 21. 24. The step of determining whether or not it is suitable for spatial multiplexing determines the degree of multiplexing when the normal allocation priority is assigned to two or more slots. 23. The slot allocation program according to any one of 23. 25. The step of determining whether or not it is suitable for the spatial multiplexing determines the degree of multiplexing based on the received power level from the mobile terminal apparatus that requires the slot allocation. 25. The slot allocation program according to any one of 1 to 24. 26. The step of determining whether or not suitable for the spatial multiplexing, the determination of the ease of multiplexing is performed based on the reception timing from the mobile terminal apparatus that requires the allocation of the slot. 24. The slot allocation program according to any one of 24. 27. The ease of multiplexing is determined in the step of determining whether or not it is suitable for the spatial multiplexing, based on the moving speed of the mobile terminal apparatus requesting the slot allocation. A slot allocation program according to any one of the above.