JPH09107579A - Idle channel outgoing transmission power control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the idle channel outgoing transmission power control system in which proper antenna diversity is selected with a required minimum idle channel outgoing transmission power. SOLUTION: A base station 30 informs prescribed threshold level information through an outgoing control channel to a mobile station 10 and the mobile station 10 decides an idle channel outgoing transmission power of the base station based on a level difference between the informed threshold level information and a reception level of the outgoging control channel and informs the transmission power to the base station 30 through an incoming control channel. The base station 30 uses the informed idle channel outgoing transmission power as its own idle channel outgoing transmission power. Preferably the base station 30 energizes the outgoing transmission power of the idle channel by the level measurement slot for antenna diversity selection by the mobile station 10 to which the speech channel is allocated. Or the base station 30 energizes the outgoing transmission power of the idle speech channel by the level measurement slot level measurement time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an idle channel downlink transmission power control system, and more particularly, when a slot other than a slot to which a speech channel is assigned in a TDMA (Time Division Multiple Access) type mobile communication system is an idle channel. The present invention relates to an idle channel downlink transmission power control method.

[0002] In this type of mobile communication system, the base station uses the empty slot if another slot of the same TRX (transceiver) as the slot of the speech channel assigned to the mobile station is an empty channel. Then, in order to measure the reception level for antenna diversity, the idle channel downlink transmission power is sent also to the idle slot.

[0003]

20 to 26 are diagrams (1) to (7) for explaining a conventional technique. FIG. 20 shows an example of a mobile communication system, in which 1 is a fixed telephone (TE),
3 is a public network, 4 is a mobile relay exchange, 10 ₁ to 10 _n are mobile stations (MS), 30 ₁ to 30 _n are base stations (BS), 5
Reference numeral 0 is a radio network controller (MCS).

In the mobile station 10, 11 is a speaker (S
P), 12 is a console (CSL) equipped with a liquid crystal display and dial keys, 13 is a microphone (MC), 14
Is a control unit (including a TDMA communication control unit) that performs main control of the mobile station, 15 is a transmission unit using the π / 4 shift QPSK system, 16 is a frequency synthesizer, and 17 is a π / 4 shift QP.
SK system receiver, 18 is a reception level measuring unit (RS
SIDT), 19 is an antenna changeover switch, 20 is a duplexer (DVP), 21 and 22 are antennas of a reception diversity structure.

In the base station 30, 31 is an antenna shared unit, 32 _{1 to} 32 _n are transmission / reception units (VTRX 1 to VTRXn) for communication channels, 33 is a transmission / reception unit (DTRX) for channels including a control channel, Reference numeral 35 is a control unit of the base station. Further, in the radio network controller 50, 51
Is a call path switch unit, 52 is a wireless line (call channel,
It is a control unit that controls a control channel and the like).

The operation of the conventional idle channel downlink transmission power control will be described below, focusing on the mobile station a and the base station A. FIG. 21 is a diagram for explaining downlink base station transmission power control when a mobile station makes a call. In FIG. 21, reference numeral 41 denotes a busy / empty channel transmission power control unit for controlling transmission power switching between a busy channel and an empty channel, and VTRX. Is a transmission / reception unit having a downlink transmission power control function for 3 slots 0 to 2 minutes, 42 is a maximum transmission power value generation unit, 43 is an initial transmission power value generation unit, and 44 is a transmission power control unit.

The base station A periodically transmits a "broadcast information" signal through the downlink control channel. FIG. 24 shows the signal format of the broadcast information. The mobile station a measures the reception level of each downlink control channel in its own zone and the peripheral zone when it waits for itself and stores it in the memory. Then, the mobile station a
When calling the mobile station b or the fixed telephone c, the base station A
The “outgoing wireless status report” of FIG. The transmission wireless status report includes the reception levels of the own zone and the surrounding zones measured during the standby.

When the base station A receives the outgoing radio condition report, it notifies the radio network controller 50 of this. When the reception level of the own zone (zone A in this example) satisfies the quality sufficiently, the control unit 52 of the wireless line control station 50 determines the empty call channel of the own zone based on the notified outgoing radio state report. Allocate and notify base station A.

The base station A notifies the assigned communication channel to the mobile station A by "designation of radio channel" in FIG. 25 (B) and shifts to the communication channel. When the mobile station a receives the radio channel designation, the mobile station a shifts to the notified call channel and starts a call. In addition, during a call from base station A /
In the empty channel transmission power control unit 41, which VTRX slot of the base station A the speech channel assigned to the mobile station a corresponds to, and the same VTR as the speech slot.
It is determined whether another slot of X is busy. In this example, slot 0 = speech slot and slots 1 and 2 = empty slot.

Then, the busy / empty channel transmission power control unit 41 in this case has an initial transmission power value (eg Pd _TCH -4 dB) for the time being for the downlink transmission power of the communication slot 0.
Set to. Here, Pd _TCH is the maximum transmission power value that the base station A can transmit. Further, the downlink transmission power of the empty slots 1 and 2 is set to the maximum transmission power value (Pd _TCH −0 dB) so that the mobile station a can perform appropriate antenna switching diversity even if it is at the far end of the zone A.

FIG. 23A shows a timing chart of downlink transmission power control in this case. Pd in the figure is P
Abbreviation for d _TCH . Incidentally, when all slots 0 to 2 = empty slots, the mobile station a does not need to select antenna diversity by using the empty slots, and therefore transmission is turned off for all three slots of the VTRX. .

FIG. 23B shows a timing chart of downlink transmission power control in this case. After that, the mobile station a during a call measures the downlink reception level of the communication slot 0 by the reception level measuring unit 18, and reports this to the base station A on the uplink communication channel. In the base station A, the reception power level report unit 44 activates the transmission power control unit 44 of the communication slot 0, and the transmission power control unit 44 receives the reception level of the communication slot 0 reported from the mobile station a. Is compared with a predetermined reference reception level (not shown) for performing downlink transmission power control, and the downlink transmission power value of the communication slot 0 is controlled so that the reception level of the mobile station a converges to the reference reception level. . This control is continued until the call in call slot 0 ends.

On the other hand, the empty slots 1 and 2 are transmitted at the maximum transmission power value until the end of the call in the call slot 0. However, when a speech channel is allocated to the empty slot 1 or 2 on the way, the same downlink transmission power control as in the case of the speech slot 0 is performed on the empty slot 1 or 2. Under such downlink transmission power control, the mobile station a during a call performs the following antenna switching diversity control according to the timing chart of FIG.

Assuming that the transmission and reception timings of the base station A are as shown in the figure, the mobile station a receives at the slot 0 of the base station transmission and receives the slot 0 of the base station reception.
There is a relationship to send in. Then, the mobile station a in this example
Antenna 2 during the antenna diversity reception level measurement section LM (for example, 1 mS) of the slot (that is, slot 2) immediately before the reception slot 0 of its own starts.
The reception levels of the antennas 1 and 22 are measured and the antenna selection unit 19 selects the antenna with the higher reception level 21/22.
Select For example, when the reception levels of the antennas 21 and 22 are 10 dBμV and 20 dBμV, respectively, the antenna 22
Choose one.

FIG. 22 is a diagram for explaining downlink base station transmission power control when a mobile station receives a call. In the same manner as described above, the mobile station a measures the reception level of each downlink control channel in its own zone and the peripheral zone during its standby. And base station A
When there is a call request from a fixed network or the like, FIG.
The signal of "call" of (A) is transmitted.

When the mobile station a receives this call, it sends to the base station A the signal "incoming radio status report" of FIG. The incoming radio status report includes the reception levels of the own zone and the surrounding zones measured during the standby. Upon receiving the incoming radio condition report, the base station A notifies the radio network controller 50 of this. Then, the radio network controller 50 allocates an empty call channel of its own zone when the reception level of its own zone (zone A in this example) satisfies the quality based on the notified outgoing radio condition report, Notify base station A. Subsequent operations are the same as in the case of the above-mentioned calling.

[0017]

As described above, in the conventional idle channel downlink transmission power control method, when one or more slots in the VTRX are assigned as speech channels, all slots of the remaining idle channels are allocated. Minutes were set to ON for downlink transmission power. In addition, the idle channel downlink transmission power value at that time is set as the maximum transmission power value that can be transmitted by the base station A so that even if the mobile station a is at the far end of the zone A, the antenna selection is not mistaken due to the reception level decrease. I was there.

However, if the system in which all the empty slots have the downlink transmission power turned on as in the above-mentioned conventional method, the mobile station a
The downlink transmission power is turned on even in a slot that is not used. Further, in the conventional method in which the idle channel downlink transmission power value is set to the maximum transmission power value that can be transmitted by the base station A, even if the mobile station a is not far from the base station A, the zone A remains in the zone A. Is transmitted with excessive transmission power.

As a result, conventionally, there arises a problem that the unnecessary downlink transmission power both in terms of time and power causes interference with other communications, and that the power consumption of the base station A increases. It was It is an object of the present invention to provide an idle channel downlink transmission power control method capable of performing proper antenna diversity selection with a minimum required idle channel downlink transmission power.

[0020]

The above-mentioned problem is solved by the structure shown in FIG. That is, the idle channel downlink transmission power control method of the present invention (1) is based on the idle channel downlink transmission power control method when a slot other than the slot to which the speech channel is allocated in the TDMA mobile communication system is an idle channel downlink transmission power control method. The station 30 notifies the mobile station 10 of predetermined threshold information on the downlink control channel, and the mobile station 1
0 determines the idle channel downlink transmission power value of the base station 30 from the level difference between the notified threshold information and the reception level of the downlink control channel, and determines this value on the uplink control channel by the base station 30.
Then, the base station 30 uses the notified idle channel downlink transmission power value as its own idle channel downlink transmission power value.

In the present invention (1), the base station 30 notifies the mobile station 10 of appropriate threshold value information corresponding to its own zone through the downlink control channel. The mobile station 10 obtains the level difference between the notified threshold information and the reception level of the downlink control channel. In this case, if you do not consider the obstacle,
If the mobile station 10 is close to the base station 30, for example, the relationship of (reception level)> (threshold information) can be satisfied. If the mobile station 10 is far from the base station 30, (reception level) <(threshold information).
Can be a relationship. That is, this level difference reflects the distance between the base station 30 and the mobile station 10. When considering obstacles, it reflects the overall communication environment between the base station 30 and the mobile station 10. In any case, this level difference serves as an appropriate index when the base station 30 sends the idle channel downlink transmission power to the mobile station 10.

Therefore, the mobile station 10 determines the idle channel downlink transmission power value of the base station 30 from this level difference and notifies the base station 30 of this via the uplink control channel.
Uses the notified idle channel downlink transmission power value as its own idle channel downlink transmission power value. Therefore, the present invention (1)
According to the above, the mobile station 10 can appropriately select antenna diversity with a small amount of idle channel downlink transmission power according to the communication environment.

The idle channel downlink transmission power control method of the present invention (2) is the idle channel downlink transmission power control method when a slot other than the slot to which the speech channel is allocated in the TDMA mobile communication system is an empty channel. The base station 30 notifies the mobile station 10 of predetermined threshold value information on the downlink control channel, and the mobile station 10 calculates a level difference between the notified threshold value information and the reception level of the downlink control channel, and information on the level difference. To the base station 30 through the uplink control channel, the base station 30 determines its own idle channel downlink transmission power value from the notified information on the level difference, and sets this as its own idle channel downlink transmission power value. Is.

According to the present invention (2), the processing load on the mobile station 10 is reduced, thus reducing the cost of the entire system. Preferably, in the present invention (3), the base station 3
0 activates the downlink transmission power of the idle communication channel only for the level measurement slot for the mobile station 10 to which the communication channel is assigned to select the antenna diversity.

Therefore, the mobile station 10 can properly select the antenna diversity with less idle channel downlink transmission power. Further, the interference given to other communication is further reduced.
Also, preferably, in the present invention (4), the base station 30
Activates the downlink transmission power of the idle communication channel for the level measurement time of the level measurement slot for the mobile station 10 to which the communication channel is assigned to select the antenna diversity.

Therefore, the mobile station 10 can properly select the antenna diversity with the minimum required idle channel downlink transmission power. Further, the interference given to other communication is further reduced. Also, preferably, in the present invention (5), the mobile station 10 classifies the obtained level differences into a free channel downlink transmission power value corresponding to the class. By classifying the obtained level difference into linear / non-linear ranges, a useful idle channel downlink transmission power value can be determined with a small amount of bit information.

Further, in the present invention (6), preferably, the mobile station 10 classifies the obtained level difference and notifies the base station 30 of the information of the level difference corresponding to the class,
In addition, the base station 30 determines the corresponding idle channel downlink transmission power value from the notified level difference information. Further, preferably, in the present invention (7), the base station 30 notifies the threshold value information by broadcast information. If the existing notification information is used, the threshold information can be efficiently notified at the optimum timing.

Further, preferably, in the present invention (8), the base station 30 notifies the threshold value information by a predetermined bit pattern using the extended information element part of the broadcast information. Also, preferably, in the present invention (9), the mobile station 10 transmits information regarding the determined idle channel downlink transmission power value or the calculated level difference to the originating radio condition report when the mobile station is called or when the mobile station is called. Notify by incoming wireless information report. If the existing outgoing radio status report or incoming radio information report is used, information regarding the determined idle channel downlink transmission power value or the calculated level difference can be efficiently notified at the optimum timing.

Further, in the present invention (10), preferably, the mobile station 10 uses the extended information element portion of the outgoing radio status report or the incoming radio status report as information regarding the idle channel downlink transmission power value or the level difference. Notify by the bit pattern of. Further, in the present invention (11), preferably, the base station 30 is used for measuring the reception level until the slot to which the communication channel is allocated is terminated or until the communication channel is allocated to the reception level measuring slot corresponding to the slot. Energize the downlink transmission power of the slot. If the transmission is turned on during this period, the purpose can be sufficiently achieved.

[0030]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Note that the same reference numerals indicate the same or corresponding parts throughout the drawings. The basic configuration of the example mobile communication system according to the present embodiment may be the same as that shown in FIG.

2 and 3 are diagrams (1) and (2) for explaining the downlink transmission power control according to the first embodiment. FIG.
FIG. 4 is a diagram illustrating base station downlink transmission power control when a mobile station makes a call, in which reference numeral 45 is a busy / empty channel transmission power control unit according to the embodiment, and 46 is a downlink channel downlink transmission power control unit. Each of the characteristic functions other than these is realized by each control unit including the CPU of the mobile station 10, the base station 30, and the radio network controller 50.

The base station A periodically transmits a "broadcast information" signal through the downlink control channel. FIG. 15 shows the signal format of the broadcast information. The main body of this notification information is shown in FIG.
Of the extended information element (section 1
The column 7) includes threshold information for the mobile station a to determine the idle channel downlink transmission power value of the base station A.

FIG. 15 shows a list of threshold values (reception level values) of each size selected according to the property (size, city area, etc.) of the own zone. A person who selects an appropriate one for each zone,
The selected one is set in the broadcast information. In this state, the mobile station a measures the reception levels of the respective downlink control channels of its own zone A and the peripheral zone while waiting for itself and stores them in the memory.

When the mobile station a makes a call to the mobile station b or the fixed telephone c, the base station A sends a "radio call status report".
The signal of is transmitted. FIG. 16 shows the signal format of the transmission wireless status report. As in the conventional case, this includes the reception levels of the own zone and the surrounding zones measured during the standby. Further, in the field of the extended information element (item 11) of this transmission wireless status report, information on the idle channel downlink transmission power value of the base station A determined by the mobile station a is written in a predetermined bit pattern.

FIG. 8 shows a flowchart of the idle channel downlink transmission power value determination processing by the mobile station a. Step S
In 1, the difference (Ld _CCH −Ltd _CCH ) between the reception level Ld _CCH of the downlink control channel of its own zone A measured at the time of standby and the threshold Ltd _CCH notified by the broadcast information is obtained, and the result is stored in the register A.

In step S2, it is checked whether A <0, and A
If <0, it means that communication is difficult, so step S
In step 7, “Pd _CCH −0 dB” is set in the register B as the idle channel downlink transmission power value. Where Pd
_CCH is the maximum transmission power value of the downlink control channel of the base station A, and is equal to the maximum transmission power value of the downlink communication channel of the base station A in this example.

If A <0 is not satisfied, it is checked in step S4 if 0≤A <4 dB. If 0≤A <4 dB, in step S8 the register B is set to "P" as in step S7.
d _{CC H} −0 dB ”. If 0 ≦ A <4 dB is not satisfied, it is checked in step S4 whether or not 4 dB ≦ A <8 dB. If 4 dB ≦ A <8 dB, the communication state is good. Therefore, in step S9, the register B stores “Pd _CCH −
4 dB ”is set.

If 4 dB≤A <8 dB is not satisfied, the reception level of the mobile station a is very strong, and therefore "Pd _CCH -8 dB" is set in the register B in step S5. In step S6, the contents of the register B are written in the outgoing radio status report (incoming radio status report when there is an incoming call). When the base station A receives the outgoing radio condition report, it notifies the radio network controller 50 of this. Control unit 5 of wireless line control station 50
If the reception level of its own zone (zone A in this example) satisfies the quality sufficiently, 2 assigns an empty communication channel of its own zone and notifies base station A based on the notified outgoing radio status report. . The base station A notifies the assigned communication channel to the mobile station A by "radio channel designation" in FIG. 25 (B) similar to the conventional one, and shifts to the communication channel.

When the mobile station a receives the radio channel designation, the mobile station a shifts to the notified call channel and starts a call. Further, in the busy / empty channel transmission power control unit 45 of the base station A, after the transition to the above-mentioned call channel, the call channel assigned to the mobile station a is determined by which VTRX of the base station A.
It is determined which of the slots corresponds to, and whether or not another slot of the same VTRX as the call slot is busy, and the following downlink transmission power control is performed.

FIG. 10 shows a flowchart of downlink transmission power control processing by the base station A. The figure shows the N-th VTRX
Call slot M in N and empty slot L immediately before it
, But slot 0
Description will be made assuming that == speech slot, slots 1 and 2 = empty slot. In step S21, the busy / empty channel transmission power control unit 45 sets, for example, (Pd _TCH -4 dB) as the initial transmission power value in the talk slot 0 of the VTRXN. Here, Pd _TCH is the maximum transmission power value that the base station A can transmit.

In step S22, it is determined whether or not slot 2 immediately before the call slot is an empty channel. In the case of an empty channel, it is the downlink transmission power value of the empty channel notified to the base station A by the mobile station a in the transmission radio status report to the empty channel transmission power control unit 46 of slot 2 in step S23, for example (Pd _CCH -8 dB) is set, and transmission is turned on for the entire section of the slot 2.

If it is not an empty channel, step S
Step 23 is skipped. Note that the slot 2 in this case has already been set to the initial transmission power value as a speech channel, or is thereafter subjected to power control by the transmission power control unit 44. Incidentally, the empty slot 1 in this example is transmitted O
This is the state of FF. In step S24, call slot 0
Determines whether the transmission power is controlled. When the mobile station a in a call measures the downlink reception level of the communication slot 0 by the reception level measuring unit 18 and reports this to the base station A on the uplink communication channel, it is determined that the transmission power is controlled. In this case, the process proceeds to step S25, where the transmission power control unit 44 of the communication slot 0 reports the reception level of the communication slot 0 from the mobile station a and a predetermined reference reception level (not shown) for performing downlink transmission power control. And the downlink transmission power value is controlled so that the reception level of the mobile station a converges to the reference reception level. If the transmission power of the call slot 0 is not controlled, the process of step S25 is skipped.

In step S26, it is determined whether or not the empty slot 2 is assigned to the speech channel. If not, it is determined in step S27 whether or not the speech slot 0 is the end of speech. If it is not the end talk, step S
Returning to step 24, if necessary, downlink power control of the communication slot 0 is performed. If it is determined in step S26 that a communication channel is assigned to the empty slot 2, then step S
In step 29, the initial transmission power value is set in the empty slot 2.

In this case, although not shown, the downlink transmission power control for the communication slots 0 and 2 is performed in parallel thereafter. If the slot 1 is empty, the empty channel downlink power setting value as the level measurement slot of the communication slot 2 is set to the empty slot 1,
The transmission is turned on for all the sections. If it is determined in step S27 that the call slot 0 has ended, the transmission of the empty slot 2 is turned off in step S28. Although not shown, the subsequent power control of the call slot 0 follows the presence / absence of a call in the immediately following slot 1.

FIG. 7A shows a timing chart of downlink transmission power control in the above case. In this example, the initial transmission power value of the communication slot 0 is (Pd _TCH -4d
B), transmission is turned off in the empty slot 1, and the downlink transmission power value of the empty slot 2 is (Pd _CCH −8 dB).
Here, the transmission power value Pd _CCH of the downlink control channel and the transmission power value Pd _TCH of the downlink communication channel are the same transmission power value, and both are the maximum transmission power value that the base station A can transmit.

Under such downlink transmission power control, the mobile station a during a call performs antenna switching diversity control according to the timing chart of FIG. FIG. 3 is a diagram for explaining base station downlink transmission power control when a mobile station receives a call. In the same manner as described above, the mobile station a measures the reception level of each control channel in its own zone and the peripheral zone while waiting.

When there is a call request from the fixed network or the like, the base station A sends the "call" signal shown in FIG. When the mobile station a receives this call,
The signal of “incoming radio status report” is sent to the base station A. FIG. 17 shows the signal format of the incoming radio status report. This includes the reception levels of the own zone and surrounding zones measured during the standby. Further, information of the idle channel downlink transmission power value of the base station A determined by the mobile station a is written in a predetermined bit pattern in the field of the extended information element (item 11) of this incoming radio status report.

Upon receiving the incoming radio condition report, the base station A notifies the radio network controller 50 of this. Then, when the reception level of the own zone (zone A in this example) satisfies the quality sufficiently, the wireless line control station 50 determines the idle call channel of its own zone A based on the notified outgoing wireless state report. Allocate and notify base station A. Subsequent operations are the same as in the case of the above-mentioned calling.

Note that, as described above, the operation of the mobile station call is different from the operation of the mobile station call only in the communication sequence on the control channel. Therefore, in each of the following embodiments, the operation when the mobile station receives the call is performed. The description of the operation is omitted. FIG. 4 is a diagram for explaining downlink transmission power control according to the second embodiment, and the figure shows base station downlink transmission power control when a mobile station makes a call.

The control according to the second embodiment is substantially the same as the control according to the first embodiment, except that if the slot 2 immediately before the call slot 0 is an empty slot, the empty slot 2 The downlink transmission power is different from the mobile station a in that the transmission is turned on only in the section LM (for example, 1 mS) in which the mobile station a measures the reception level for antenna switching diversity.

FIG. 11 shows a flowchart of the downlink transmission power control process by the base station A. The same steps as those in FIG. 10 are designated by the same step numbers and description thereof is omitted. In step S30, the empty channel transmission power control unit 46 of slot 2 is
The mobile station a, on the other hand, notifies the base station A of the transmission radio status report of the downlink transmission power value of the empty channel (Pd _CCH -8 dB).
Is set, and the transmission is turned on only in the section LM in which the mobile station a measures the reception level for antenna switching diversity among all the sections of the slot 2.

FIG. 7B shows a timing chart of downlink transmission power control in the above case. FIG. 5 is a diagram for explaining downlink transmission power control according to the third embodiment, and the figure shows base station downlink transmission power control when a mobile station makes a call.
The control according to the third embodiment is almost the same as the control according to the first embodiment, but the mobile station a calculates the level difference between the notified threshold information and the reception level of the downlink control channel. Then, the information related to the level difference is notified to the base station A via the uplink control channel, and the base station A determines its own idle channel downlink transmission power value from the notified information related to the level difference and sends it to the base station A. The difference is that it is the idle channel downlink transmission power value.

FIG. 9 shows a flow chart of the level difference calculation processing for determining the idle channel downlink transmission power by the mobile station a. The same processes as those in FIG. 8 are designated by the same step numbers and the description thereof is omitted. In step S17, 0 dB or less (less than) is set in the register B as the level difference information. Similarly, in step S18, 0 to 4 dB is applied to the register B,
The register B is set to 4 to 8 dB in step S19, and the register B is set to 8 dB or more in step S15.

FIG. 12 shows a flowchart of the idle channel downlink transmission power value determination processing in the base station A. In step S31, the information on the level difference received from the mobile station a is set in the register L. In step S32, it is determined whether or not the information related to the level difference is 0 dB or less (less than) and 0
If it is less than or equal to dB, the mobile station a is in communication difficulty, and therefore, for example, (Pd _CCH −0 dB) is set as the idle channel downlink transmission power value in the register B in step S37.

If it is not less than 0 dB, step S
In 33, it is determined whether or not the information regarding the level difference is 0 to 4 dB, and if it is 0 to 4 dB, the same (Pd _CCH −0 dB) is set in the register B in step S38. Also,
If it is not 0 to 4 dB, it is determined in step S34 whether or not the information related to the level difference is 4 to 8 dB. If it is 4 to 8 dB, the receiving state of the mobile station a is good, so step S
At (39), (Pd _CCH -4 dB) is set in the register B.

If it is not 4 to 8 dB, the mobile station a
Since the reception level of is high, register B is registered in step S35.
To (Pd _CCH −8 dB). FIG. 13 shows a flowchart of downlink transmission power control processing by the base station A. This process is executed after the idle channel downlink transmission power value determination process of FIG. 12 is executed.

The same steps as those in FIG. 10 are designated by the same step numbers and the description thereof will be omitted. In step S41, the empty channel transmission power control unit 46 of the empty slot 2
For example, (Pd _CCH −8 dB) is set as the empty channel downlink transmission power value determined in 2, and transmission is turned on for the entire section of the slot 2. FIG. 6 is a diagram for explaining downlink transmission power control according to the fourth embodiment, which shows base station downlink transmission power control when a mobile station makes a call.

The control according to the fourth embodiment is substantially the same as the control according to the second embodiment, except that when the slot 2 immediately before the call slot 0 is an empty slot, the empty slot 2 The downlink transmission power of the above is different in that the transmission is turned on only during the section LM (for example, 1 mS) in which the mobile station a measures the reception level for antenna switching diversity.

FIG. 14 shows a flowchart of the downlink transmission power control process by the base station A. This process is executed after the idle channel downlink transmission power value determination process of FIG. 12 is executed. The same processes as those in FIG. 13 are designated by the same step numbers and the description thereof is omitted. In step S42, the empty channel downlink transmission power value determined by the base station A is set to, for example, (Pd _CCH
-8 dB) is set, and the transmission is turned on only in the section LM in which the mobile station a measures the reception level for antenna switching diversity among all the sections of the slot 2.

In each of the above embodiments, the transmission is turned on only in the empty slots used for antenna switching diversity or only a part of them, but all the empty slots are transmitted.
Even with N, since the transmission level is properly selected, the effect of the present invention can be obtained. Further, it goes without saying that the transmission ON section of the vacant slot is not limited to the above embodiment and can be arbitrarily selected.

Although a plurality of preferred embodiments of the present invention have been described above, it goes without saying that various modifications of the configuration, control, and combinations thereof can be made without departing from the spirit of the present invention. There is no.

[0062]

As described above, according to the present invention, proper antenna diversity selection can be performed with the minimum required idle channel downlink transmission power, interference with other communications can be prevented, and more reliable mobile communications can be achieved. You can build a system.
Moreover, power saving can be achieved by preventing high transmission power.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of the present invention.

FIG. 2 is a diagram (1) illustrating downlink transmission power control according to the first embodiment.

FIG. 3 is a diagram (2) illustrating downlink transmission power control according to the first embodiment.

FIG. 4 is a diagram illustrating downlink transmission power control according to the second embodiment.

FIG. 5 is a diagram for explaining downlink transmission power control according to the third embodiment.

FIG. 6 is a diagram for explaining downlink transmission power control according to the fourth embodiment.

FIG. 7 is an operation timing chart of downlink transmission power control according to the embodiment.

FIG. 8 is a diagram (1) illustrating a control flow according to the embodiment.

FIG. 9 is a diagram (2) illustrating a control flow according to the embodiment.

FIG. 10 is a diagram (3) illustrating a control flow according to the embodiment.

FIG. 11 is a diagram (4) illustrating a control flow according to the embodiment.

FIG. 12 is a diagram (5) illustrating a control flow according to the embodiment.

FIG. 13 is a diagram (6) illustrating a control flow according to the embodiment.

FIG. 14 is a diagram (7) illustrating a control flow according to the embodiment.

FIG. 15 is a diagram (1) illustrating an information communication format according to the embodiment.

FIG. 16 is a diagram (2) illustrating an information communication format according to the embodiment.

FIG. 17 is a diagram (3) illustrating an information communication format according to the embodiment.

FIG. 18 is a diagram (4) explaining an information communication format according to the embodiment.

FIG. 19 is a diagram (5) illustrating an information communication format according to the embodiment.

FIG. 20 is a diagram (1) illustrating a conventional technique.

FIG. 21 is a diagram (2) illustrating a conventional technique.

FIG. 22 is a diagram (3) illustrating a conventional technique.

FIG. 23 is a diagram (4) illustrating a conventional technique.

FIG. 24 is a diagram (5) illustrating a conventional technique.

FIG. 25 is a diagram (6) illustrating a conventional technique.

FIG. 26 is a diagram (7) illustrating a conventional technique.

[Explanation of symbols]

 10 mobile station 30 base station 50 wireless circuit control station

Claims (11)

[Claims] 1. In an idle channel downlink transmission power control method when a slot other than a slot to which a speech channel is assigned in a TDMA mobile communication system is an idle channel downlink transmission power control method, a base station moves predetermined threshold value information on the downlink control channel. The mobile station, the mobile station determines the idle channel downlink transmission power value of the base station from the level difference between the notified threshold information and the reception level of the downlink control channel, and determines this to the base station on the uplink control channel. Notifying, and the base station sets the notified idle channel downlink transmission power value as its own idle channel downlink transmission power value. 2. In an idle channel downlink transmission power control method when a slot other than a slot to which a speech channel is assigned in a TDMA mobile communication system is an idle channel downlink transmission power control method, a base station uses predetermined threshold information on a downlink control channel as a mobile station. The mobile station notifies the base station on the uplink control channel of the information about the level difference by calculating the level difference between the notified threshold information and the reception level of the downlink control channel, and the base station is A vacant channel downlink transmission power control method, characterized in that the vacant channel downlink transmission power value of the vacant channel is determined from the notified information about the level difference and is set as the vacant channel downlink transmission power value of the vacant channel. 3. The base station activates the downlink transmission power of a vacant speech channel only in the level measurement slot for the mobile station to which the speech channel is assigned to select antenna diversity. Downlink transmission power control method for idle channels. 4. The base station activates the downlink transmission power of the idle communication channel for the level measurement time of the level measurement slot for the mobile station to which the communication channel is assigned to select the antenna diversity. Item 1
Or, the idle channel downlink transmission power control method of 2. 5. The idle channel downlink transmission power control method according to claim 1, wherein the mobile station classifies the obtained level differences and determines an idle channel downlink transmission power value corresponding to the class. 6. The mobile station classifies the obtained level difference and notifies the base station of the information of the level difference corresponding to the class, and the base station corresponds to the available channel from the notified information of the level difference. 3. The idle channel downlink transmission power control method according to claim 2, wherein the downlink transmission power value is determined. 7. The idle channel downlink transmission power control method according to claim 1, wherein the base station notifies the threshold value information by broadcast information. 8. The idle channel downlink transmission power control method according to claim 7, wherein the base station notifies the threshold value information by a predetermined bit pattern using the extended information element part of the broadcast information. 9. The mobile station notifies the information regarding the determined idle channel downlink transmission power value or the calculated level difference by a calling radio status report when the mobile station makes a call or an incoming radio information report when the mobile station receives a call. 3. The idle channel downlink transmission power control method according to claim 1 or 2. 10. The mobile station notifies the information related to the idle channel downlink transmission power value or the level difference by a predetermined bit pattern using the extended information element part of the outgoing radio status report or the incoming radio status report. The idle channel downlink transmission power control method according to claim 9. 11. The base station until the slot to which the speech channel is allocated ends, or until the speech channel is allocated to the reception level measurement slot corresponding to the slot.
5. The idle channel downlink transmission power control method according to claim 1, wherein the downlink transmission power of the reception level measuring slot is activated.