JP2002058061A - Assignment method of physical slot by adaptive array base station - Google Patents

Abstract

(57) [Problem] To provide a method of allocating physical slots by an adaptive array base station capable of establishing and maintaining a spatially multiplexed call using the same GOS as a normal non-spatial multiplexed call. SOLUTION: When a new call request is made in a state where the TCH physical slot of the base station is full, as a result of the above-described level division performed in an existing call, it corresponds to level A or level B. It is checked whether there are two or more calls to be made (S307).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an SDMA (Space Div.)
The present invention relates to a communication system of the ision Multiple Access (spatial division multiple access, hereinafter referred to as “spatial multiplex”) system, and uses the same TCH (information channel or speech channel) as another user by spatial multiplexing a user at an adaptive array base station. ) This relates to a method of assigning a physical slot.

[0002]

2. Description of the Related Art In recent years, in a digital communication system (particularly, a PHS) of a mobile communication terminal, a plurality of calls are established in the same physical slot by spatial multiplexing.

[0003]

SUMMARY OF THE INVENTION However, WLL
Unlike spatial multiplexing technology in fixed wireless communication systems such as wireless local loop (Wireless Local Loop) systems, mobile communication terminals such as PHS have not yet reached practical use due to various problems and restrictions. It is. This is because the mobile communication terminal may have a large dynamic range (Dynamic Range) of the user or a high speed of the user, and even if a plurality of user calls are established by spatial multiplexing, GOS (Grade of service) is poor, and interference avoidance is often performed to prevent spatial multiplexing from being maintained.

[0004] As described above, the spatial multiplexing call has a greater risk from the GOS perspective than otherwise, and it is often the case that an attempt to actively process a spatial multiplexing call results in the GOS.
May not be acceptable. In addition, establishing a call by spatial multiplexing for a user who has newly requested a call on the CCH (control channel) requires an uplink RSSI of the user.
The risk is very large because there is no information on the dynamic range and speed of (reception strength). An object of the present invention is to provide a method of allocating physical slots by an adaptive array base station capable of establishing and maintaining a spatially multiplexed call using the same GOS as a normal non-spatial multiplexed call. I do.

[0005]

In order to solve the above-mentioned problems, a method of allocating a physical slot by an adaptive array base station according to the present invention uses a maximum transmission power for a mobile communication terminal to be transmitted. By using adaptive beamforming for communication and adaptive null steering that does not affect the interfering mobile communication terminal, communication in the SDMA scheme in which the same physical slot is shared by a plurality of calls. In the method of allocating physical slots by the adaptive array base station which performs the above, one physical slot is allocated to one call until the physical slots of the own station are exhausted.
SSI dynamic range and Spatial Signature
(Reception response vector) is calculated, and the existing call is classified into levels based on the calculation result. Check if there are multiple existing calls of level or higher, and if not, send control data to reject the assignment to the mobile communication terminal that issued the request to establish a new call. If so, check how many exist, and if there are two, make one of these two existing calls TCH switch to the physical slot used by the other call, and use the SDMA method. And assigns an empty physical slot to be switched to to a new call, and when there are three or more, ranks those calls based on the calculation result and selects one of the top two existing calls. And to communicate with SDMA system by TCH switch to the physical slot using the other hand of the call and allocates a switching source free physical slots to the new call.

In the method of allocating a physical slot by the adaptive array base station according to the present invention, a data block for a call type identifier is provided in an establishment request message sent from a mobile communication terminal to the adaptive array base station, and a physical block of the own station is provided. When a request for establishing a new call is received in a state where there is no more free space in the slot, when only one existing call of a predetermined level or higher exists, a new call type is identified from the call type identifier, and a new call type is identified. If the call type corresponds to a predetermined type, the RSSI of the CCH of the new call and the TSI of the existing call
The difference from the average value of the RSSI of the CH is determined, and when the difference is equal to or less than the specified value, the physical slot used by the existing call is shared with the new call, and communication is performed in the SDMA method. I do.

Preferably, the predetermined types are short message and data communication. In some cases, location registration may be applied. In addition, two TDMA physical slots can be used in the SDMA system.
If a TCH physical slot becomes vacant after one call is established, it is preferable to switch one of the two calls performing SDMA communication to the vacant physical slot.

The monitor information on the dynamic range of the uplink RSSI and the change speed of the Spatial Signature (reception response vector) used for determining whether or not to perform the communication in the SDMA system is based on the communication in the SDMA system. And the dynamic range of the uplink RSSI and Spat for each call until the call ends.
The monitoring of the changing speed of the ial Signature (reception response vector) is continued.

Further, in order to solve the above-mentioned problem, the operation method of the adaptive array base station according to the present invention is based on the SDM
The failure rate and the GOS index data in the communication in the A-system are recorded at a fixed period for each base station, and the failure rate is higher than a predetermined reference for a base station or the GOS index data does not satisfy a predetermined reference. Is characterized in that communication in the SDMA system is stopped for a certain period.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the accompanying drawings, a method of allocating a physical slot by an adaptive array base station according to the present invention is applied to a PHS base station which is an adaptive array base station for digital radio communication. Embodiments will be described in detail. 1 is a functional block diagram of the adaptive array base station, FIG. 2 is a diagram showing a radiation pattern of a radio wave, and FIGS. 3 to 5 are processing flowcharts of the adaptive array base station.

Referring to FIG. 1, there is shown a functional block diagram showing an embodiment when an adaptive array base station according to the present invention is applied to a PHS base station which is an adaptive array base station for digital radio communication. . In FIG. 1, adaptive array base station 10 according to the present embodiment
Has four antennas ANT <b> 1 to ANT <b> 4, and these antennas ANT are connected to the transmission / reception switch 12. The transmission / reception switch 12 controls these antennas ANT1 to ANT4 in a time-division manner to perform switching control between transmission and reception. The transmission / reception switch 12 includes a reception module 14 and a transmission module 2.
2 are connected.

The receiving system module 14 includes the antennas AN
4 low-noise amplifiers (LNA) 1 for each T
6, a down converter (D / C) 18 and an A / D converter (A / D) 20. The receiving system module 14 is also connected to the modem unit 30, and the low noise amplifier 16, the down converter 18 and the A / D converter (A / D) 20 are transmitted from the transmission / reception changeover switch 12, which is a signal path, to the modem unit 30. They are connected in order.

Similarly, the transmission system module 22 includes four D / A converters (D / A / D converters) provided for each antenna ANT.
A) 24, an upper converter (U / C) 26, and multiplication circuits (MP) 28a and 28b. The transmission system module 22 is also connected to the modem unit 30, and the D / A
The converter 24, the upper converter 26, and the multiplying circuits 28a and 28b are connected in this order from the modem unit 30, which is a signal path, to the transmission / reception system switch 12. When spatial multiplexing is performed on two calls, a multiplying circuit 28a and a multiplying circuit 28b are used so that each call can be transmitted with a different weight.

The modem section 30 is composed of a plurality of CPUs, and performs modulation / demodulation of transmission / reception data and phase control by digital signal processing. Specifically, the following 5
Perform one control. 1. The digital signal converted in the final stage of the receiving module 14 is combined and demodulated so that, for example, D / U (Desire / Undesire: desired wave / interference wave) becomes maximum. 2. The phase of reception at the antenna ANT is calculated, and control is performed so that the phase at the antenna end becomes equivalent at the time of transmission. As a result, directivity can be provided for both transmission and reception in the direction of the PHS terminal that performs communication. 3. Suppression is achieved by creating a null point in the arrival direction of the interference wave and the delayed wave. 4. By controlling the phases of the signals supplied to the n antennas, it is possible to transmit the beam by narrowing down the beam with directivity in an arbitrary direction. 5. Interference in the downlink direction is reduced with respect to peripheral base stations and terminals other than the user terminals that are engaged in a call or exchange data (communication).

The modem unit 30 is connected to a control unit 32. The control unit 32 includes a plurality of CPUs, and controls the entire adaptive array base station 10. Specifically, the following six controls are performed. 1. It instructs the necessary parameters and timing to the modem unit 30, and processes the data received by the modem unit 30. Further, data to be radiated in the air is created and passed to the modem unit 30. Further, it instructs the control of the transmission output based on the weight calculated by the calibration. 2. A change rate of a Spatial Signature (reception response vector) from a user terminal (a PHS terminal of the user, hereinafter simply referred to as a user) is calculated. 3. Statistical processing of the uplink RSSI from the user is performed. 4. The physical slot assignment of the spatial multiplexing is performed by logic such that the GOS of the spatially multiplexed call becomes as similar as possible to the GOS of the normal call that is not the spatial multiplexing. 5. When a call is established to a plurality of users by spatial multiplexing, each user is set so that the C / I (Carrier / Interference) for each user is equal to or more than a value necessary for maintaining the GOS of the user well. Calculate the weight to. 6. It is connected to the ISDN line and executes the processing of the interface with it.

The power supply unit 34 is a power supply unit that receives a power supply of 100 V and supplies power to the adaptive array base station 10. Note that a digital signal processing unit is formed by the modem unit 30 and the control unit 32. In the adaptive array base station 10, based on received information (amplitude and phase) received from N (N is a natural number of 2 or more) antennas,
Adaptive array transmission is performed for each antenna with predetermined weighting.

When a call is established by spatial multiplexing in a mobile communication system such as a PHS, there are two major restrictions on the base station as follows. (1) Uplink R from multiple users capable of maintaining spatial multiplexing
There is a limit to the dynamic range of SSI. (2) The speed of a plurality of users who can maintain spatial multiplexing is limited.

First, the above (1) will be described in detail. When a plurality of users share the same physical slot in the adaptive array base station to establish a call by spatial multiplexing, the gain received by each user increases. Adaptive Beam Forming
At the same time, it is necessary to transmit null to other users by Adaptive Null Steering. Therefore, in order for the user to receive with good GOS, C / N (Carrier / Noise) above a certain standard
Is required. Therefore, if the base station can not create a null above a certain standard for other users,
The user's GOS becomes unacceptable.

Referring to FIG. 2, there is shown a radiation pattern of a radio wave when a call is established by spatial multiplexing. As can be seen from the figure, adaptive beamforming is performed so that the gain received by USER1 is increased, and at the same time, USER2 is received.
Null is transmitted to USER3 by adaptive null steering. Similarly, adaptive beamforming is performed so that the gain received by USER2 (USER3) is high, and at the same time USER1 and USER3 (USER1 and USER3)
Null is transmitted by adaptive null steering for 2).

In general, this null capability depends on the C / I of the base station.
Function. Considering a call with a certain user, reception from other users becomes an interference wave, and therefore, an increase in the dynamic range of the uplink RSSI from a plurality of users means that the absolute value of the C / I of the base station is correspondingly increased. It means getting bigger. The dynamic range of C / I in which the base station can secure nulls above a certain reference is finite depending on the algorithm. For example, if it is ± 20 dB, the dynamic range of the upstream RSSI must also be within ± 20 dB.

Next, "(2) Speed of a plurality of users who can maintain spatial multiplexing is limited" will be described in detail. The PHS terminal performs communication by the TDD / TDMA system, and therefore receives data from the base station. Send after ms. The adaptive array base station determines the downlink weight based on the information received from the user and reflects the weight on the transmission 2.5 ms later. That is, there is a delay of 2.5 ms. Therefore, if the speed of the user is high, the error of the weight becomes large, and a necessary null cannot be secured. The speed mentioned here is not only the moving speed (mobility) of the user,
The speed at which information received from the user changes. In the present embodiment, the “speed at which the information received from the user changes” is calculated as the changing speed of the Spatial Signature (reception response vector). For example, even if the mobility of the user is small, the speed of change of the received information may increase due to the influence of multipath depending on the surrounding environment. In order to maintain spatial multiplexing, as described above, it is necessary to secure null for a certain user over a certain standard.
The user's speed must also be below a certain standard.

Because of the above two restrictions (1) and (2), there is a risk that the user's GOS will deteriorate if a call is actively established by spatial multiplexing in a mobile communication system. Therefore, GOS of a call established by spatial multiplexing
A special channel assignment algorithm is required so that is as similar as possible to the GOS of a normal call.

The channel allocation algorithm will be described by taking spatial multiplexing by two multiplexing as an example. 1) Allocate a call to a normal channel until the base station physical slot is full. 2) For a call assigned to a common channel, two points, the dynamic range and the speed of the user's uplink RSSI, are monitored by a method described later. 3) The user's upstream RSSI is monitored by the monitor in 2).
, The following dynamic range and speed are calculated and the following level division is performed. 4) As a result of the level division in 3), it is assumed that calls belonging to the following level A or level B can share a physical slot as a spatial multiplexing channel.

<Level A> Dynamic range of upstream RSSI ≦ Range_A and SpatialSignat from user
ure (reception response vector) change speed within tolerance <Level B> Upward RSSI dynamic range ≦ Ran
ge_B and the change speed of the SpatialSignature (reception response vector) from the user is within the tolerance. <Level C> Dynamic range of upstream RSSI ≦ Ran
ge_C and the change speed of the Spatial Signature (reception response vector) from the user is within an allowable range. However, Range_C>Range_B> Range_A. Note that the above level division is merely an example, and the number of levels and the definition of each level are not limited to this.

Next, an existing call monitoring method will be described. A) The RSSI is recorded for each burst without CRC error and UW error from the user, and the level fluctuation range of the upstream RSSI is recorded. B) The changing speed (d) of the Spatial Signature (reception response vector) is recorded for each burst without CRC error and UW error from the user. The change speed (d) of the Spatial Signature (reception response vector) is defined as follows.

Spatial Signature at a certain time t _n
(Reception response vector)

(Equation 1) And the Spatial Signature (reception response vector) after 5ms
To

(Equation 2) Then, the changing speed of the Spatial Signature (reception response vector) is expressed as follows.

(Equation 3)

Next, the Spatial Signature (reception response vector) of the user will be described. In an adaptive array base station consisting of n antennas, the receiving unit weights the received signal received by each antenna by the reception weights and combines the final output.

(Equation 4) Is represented as follows.

(Equation 5)

Here,

(Equation 6)

(Equation 7)

(Equation 8)

(Equation 9) Is the Spatial Signature (reception response vector) from the user,

(Equation 10) Is the Spatial Signature (received response vector) from the interfering user,

[Equation 11] Is the receiving Weights,

(Equation 12) Is the transmission signal output by the user,

(Equation 13) Is the transmitted signal output by the interfering user,

[Equation 14] Is a noise vector.

The equation shows the case where there is one interfering user. When the adaptive array operates ideally, [Equation 8] is controlled to satisfy the following two equations.

(Equation 15)

(Equation 16)

The rate at which the received signal from a user in a talking state changes can be estimated using an equation. Spatial Signature (reception response vector) used in the formula
Is [Equation 9]. Specifically, it is determined whether the speed is acceptable as a spatial multiplexing channel in the following procedure. 1) The value of P ₁ % is extracted from the smaller d calculated every T ₁ msec and put into the histogram. 2) A ratio that satisfies d ≧ Speed_Thresh is calculated from a histogram created when T ₂ seconds have elapsed since the operation 1) was started. 3) The work of 2) is continued until the call is terminated. 4) When the ratio satisfying d ≧ Speed_Thresh is P ₂ % or more, it is determined that the spatial multiplexing channel is acceptable.

The above is monitored and recorded until the call ends, regardless of whether the call uses the spatial multiplexing channel. However, this monitoring result is assumed to be invalid if the specified time (for example, ymsec) has not elapsed since the monitoring was started, and is set to level C. In addition, the monitor information on the dynamic range of the uplink RSSI and the change speed of the Spatial Signature (reception response vector) used to determine whether or not to perform spatial multiplexing is retained during spatial multiplexing.

Referring to FIG. 3, the first step when the adaptive array base station assigns a physical slot to a new call is described.
A processing flow diagram according to the embodiment is shown. FIG.
When there is a request to establish a new call in S301 of TC,
It is checked whether the H physical slot is full (no free space) (S303). At this time, if not full, a new call is allocated to an empty physical slot (S305).

On the other hand, when a new call request is made in a state where the TCH physical slot of the base station is full, as a result of the above-described level division, a predetermined level (in this case, It is checked whether there are two or more calls corresponding to Level A or Level B, and the change rate of the Spatial Signature (reception response vector) from the user is within an allowable range (S307). As a result, if there is no such data, control data for rejecting assignment to a new call is transmitted on the CCH (S309).

As a result of S307, if there are two or more, it is checked whether there are three or more (S31).
1). If the result of S311 is three or less (that is, two), one of the two calls is transferred to the other physical slot by T.
CH switching is performed, and two calls are established by spatial multiplexing while sharing one physical slot (S313). And
A newly requested call is established in an empty physical slot (S315).

As a result of S311, if there are three or more, the above-mentioned dynamic range of the upstream RSSI, Spatial
Based on the changing speed of the Signature (reception response vector), the corresponding existing call is ranked (S31).
7). Then, one of the top two calls suitable for spatial multiplexing is switched to another physical slot by TCH, and one physical slot is shared to establish two calls by spatial multiplexing (S319). Subsequently, a newly requested call is established in an empty physical slot (S321).

Referring to FIG. 4, the second step when the adaptive array base station allocates a physical slot to a new call is described.
A processing flow diagram according to the embodiment is shown. The second embodiment requires the following prerequisites.
Normally, the user sends an establishment request message to the base station on CCH before moving to TCH. In the present embodiment, a data block for an identifier (call type identifier) capable of identifying the type of call is provided in the establishment request message so that the base station can identify the type of call in advance. There are the following types of calls in PHS.

(1) Voice (2) Location registration (3) Short message (4) Data communication Among these, (3) Short message and (4) Data communication calls are relatively mobile and uplink RSSI.
Is considered to have a small dynamic range, making it a good candidate for assignment to spatial multiplexing channels. Also, due to the nature of the call, even if the location registration fails, the terminal automatically retries until it succeeds without being conscious of the user. Therefore, the location registration may be a candidate to be assigned to the spatial multiplexing channel. In the present embodiment, (3) short message and (4) data communication are cited as the types of calls suitable for the spatial multiplexing channel. However, these two are only specific examples, and are not specific examples. It is obvious that the present invention is not limited to this as long as the dynamic range of the RSSI is small.

Conversely, (1) voice is for mobility or uplink RS
Since it is expected that the dynamic range of the SI is large, it is very risky from a GOS point of view to assign a user's call requested on the CCH to a direct spatial multiplexing channel. Therefore, the direct allocation to the spatial multiplexing channel is applied in the spatial multiplexing channel allocation algorithm of the present embodiment.

When there is a request to establish a new call in S401 of FIG. 4, the TCH physical slot is full (no free space).
Is determined (S403). At this time, if not full, a new call is allocated to an empty physical slot (S405). On the other hand, when a new call request is made in a state where the TCH physical slot of the base station is full, as a result of the above-described level division,
It is checked how many existing calls correspond to A or level B (S407). As a result, if none exist,
Control data for rejecting assignment to a new call is transmitted on the CCH (S421). On the other hand, if there is only one, the process proceeds to the process A (FIG. 5) described later (S419).

As a result of S407, if there are two, one of the two calls is switched to the other physical slot for TCH, and one physical slot is shared to establish two calls by spatial multiplexing. (S415). Then, the newly requested call is established in the free physical slot (S417).
As a result of S407, if there are three or more, the above-mentioned dynamic range of the upstream RSSI, Spatial Signatur
Based on the change speed of e (reception response vector), the corresponding existing calls are ranked (S409). Then, one of the top two calls suitable for spatial multiplexing is switched to another physical slot by TCH, and one physical slot is shared to establish two calls by spatial multiplexing (S41).
1). Subsequently, a newly requested call is established in an empty physical slot (S413).

Referring to FIG. 5, there is shown a flowchart of the process A described above. In step S501, it is determined whether an existing call that can share a physical slot belongs to the highest level (in this case, level A). As a result, if they do not belong, C
The control data for rejecting the assignment to the new call is transmitted on the CH (S509). If it belongs to level A, the type of the newly requested call is confirmed from the "call type identifier" of the received establishment request message (S50).
3). As a result, if the type of the call is “short message” or “data communication”, the process proceeds to the next process (S505). In the case of other types, control data for rejecting assignment to a new call is transmitted on CCH (S50).
9).

As a result of S 505, “RSSI of CCH of newly requested call” and “RSI of existing call belonging to level A”
If the difference between the “SI average values” is within the specified value (± XdBuV), the requested call is spatially multiplexed and established in the same physical slot as the existing level A call (S507). If not, control data for rejecting assignment to a new call is transmitted on the CCH (S509).

Next, a method of operating an adaptive array base station that supports spatial multiplexing will be described. 1) When another physical slot is vacated while maintaining a two-user call by spatial multiplexing, a call of one of the two users is moved to the vacated physical slot by switching the TCH (normally, the error rate FER). Switch many calls). This is because a normal non-spatial multiplex call is much more advantageous from a GOS perspective than a spatial multiplex call. 2) Data indicating the failure rate or GOR of a spatially multiplexed call (T
The number of CH switching, the number of handovers, the number of abnormal disconnections, etc.) are recorded at a constant period for each base station (for example, daily recording). 3) If a failure rate of a spatially multiplexed call is high, or if a base station in which data indicating GOS is significantly worse than a normal non-spatial multiplexed call is found, the environment of the base station may not be suitable for spatial multiplexing. Stop establishing a call with spatial multiplexing for a period of time (eg, until the cause is known). As described above, according to the present invention, it is possible to establish and maintain a spatially multiplexed call using the same GOS as an ordinary call without spatial multiplexing.

Also, since a call can be established on a spatially multiplexed channel with an acceptable GOS, the unit cost per channel of the base station can be reduced and the frequency can be effectively used. Further, when the installation environment of the base station is not suitable for spatial multiplexing, the spatial multiplexing service in the base station area can be stopped, so that the network quality can be prevented from deteriorating. In this embodiment, the physical slot allocation method by the adaptive array base station according to the present invention is applied to a PHS base station. However, the present invention is not particularly limited to a PHS base station.
DC (Personal Digital Cellular) and CDMA (Code Di
The present invention can be similarly applied to base stations such as vision multiple access.

As described above, according to the method of allocating physical slots by the adaptive array base station of the present invention, a spatially multiplexed call can be established and maintained by the same GOS as a normal non-spatial multiplexed call.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an embodiment when a method of allocating physical slots by an adaptive array base station according to the present invention is applied to a PHS base station.

FIG. 2 is a diagram showing a radiation pattern of a radio wave when the SDMA method is applied.

FIG. 3 is a processing flow chart for explaining the first embodiment of the present invention.

FIG. 4 is a processing flowchart illustrating a second embodiment of the present invention.

FIG. 5 is a processing flowchart for explaining a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Adaptive array base station 12 Transmission / reception changeover switch 14 Receiving module 22 Transmitting module 30 Modem part 32 Control part

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 5J021 AA04 DB05 EA04 FA06 FA13 FA16 GA06 GA08 HA06 HA10 5K022 FF00 5K059 CC07 DD24 DD27 DD35 5K067 AA13 AA23 AA41 CC24 DD30 DD47 DD51 EE10 EE65 EE71 FF36 GG08 HKK22 KK08 KK08 JJ

Claims (6)

[Claims] 1. An adaptive beamforming system which communicates with a mobile communication terminal to be transmitted at a maximum transmission power, and an adaptive null steering which does not affect an interfering mobile communication terminal. In the method of allocating physical slots by the adaptive array base station which performs communication in the SDMA scheme in which the same physical slot is shared by a plurality of calls, one call is used until the physical slots of the own station are exhausted. One physical slot is allocated to each call, and for each call, the uplink RSSI
Calculates the dynamic range and the speed of change of the Spatial Signature (reception response vector), classifies existing calls based on the calculation result, and establishes a new call in a state where there is no more free space in its own physical slot. If a request is received, it is checked whether there are a plurality of existing calls of a predetermined level or higher.If there are not a plurality of existing calls, the mobile communication terminal which has issued the new call establishment request Control data is transmitted, and if there are two or more, check how many exist, and if there are two, either one of these two existing calls is replaced with the physical slot used by the other call. Let TCH switch to S
The communication is performed by the DMA method, and the vacant physical slot of the switching source is assigned to the new call. When three or more exist, the calls are ranked based on the calculation result. One of the TCHs is switched to the physical slot used by the other call, and
A method of allocating a physical slot by an adaptive array base station, wherein communication is performed in an MA system, and a free physical slot of a switching source is allocated to the new call. 2. The method of claim 1, wherein a data block for a call type identifier is provided in an establishment request message sent from the mobile communication terminal to the adaptive array base station. In the case where a request for establishing a new call is received in a state where the physical slot of the station is full, when there is only one existing call of the predetermined level or more, the type of the new call is determined from the call type identifier. If the type of the new call corresponds to a predetermined type, the RSSI of the CCH of the new call and the TSI of the existing call
The difference from the average value of the RSSI of the CH is determined. If the difference is equal to or less than the specified value, the physical slot used by the existing call is shared with the new call, and the SDM is used.
A method of allocating physical slots by an adaptive array base station, wherein communication is performed in the A method. 3. The method of allocating physical slots by an adaptive array base station according to claim 2, wherein the predetermined type is a short message, data communication, and / or location registration. A method for allocating physical slots by a base station. 4. A method for allocating physical slots by the adaptive array base station according to claim 1, wherein two calls are established in one TCH physical slot by the SDMA method, and then the TCH physical slot is set. A method of allocating a physical slot by an adaptive array base station, characterized in that, when a vacancy occurs, one of two calls performing SDMA communication is switched to a vacant physical slot by TCH. 5. The method of allocating a physical slot by the adaptive array base station according to claim 1, wherein the uplink RSSI used for determining whether or not to perform communication in the SDMA scheme. Dynamic range and Spatial
Monitor information on the change speed of the signature (reception response vector) is maintained during communication in the SDMA system, and the upstream RSSR is maintained for each call until those calls are completed.
A method for allocating physical slots by an adaptive array base station, characterized by continuing to monitor a dynamic range of I and a change speed of a spatial signature (reception response vector). 6. An adaptive beamforming for communicating with a maximum transmission power to a mobile communication terminal to be transmitted, and an adaptive null steering for not affecting an interfering mobile communication terminal. This is an operation method of an adaptive array base station that performs communication in the SDMA system in which the same physical slot is shared by a plurality of calls by using the same physical slot. The failure rate and the GOS index data in the communication in the SDMA system are The base station or the GOS, wherein the failure rate is recorded at a fixed period for each base station,
For base stations whose index data does not meet the predetermined criteria,
An operation method of an adaptive array base station, wherein communication in the SDMA system is stopped for a certain period.