JPH09289670A - Synchronization establishing method in cdma mobile communication system, base station equipment and mobile station equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely establish synchronization of a radio channel in the case of soft hand-over by setting a time of a synchronization establishing wait timer longer in the case of the soft hand-over. SOLUTION: Synchronization is established for a radio channel within several seconds being a first prescribed time at setup of the radio channel attended with outgoing/incoming call connection, and when the synchronization is not established within this time limit, the synchronization establishment is stopped. In the case of setting up a radio channel attended with soft handover, synchronization is established for a radio channel within several tens of seconds being a second prescribed time Y1, Y2 longer than the 1st prescribed time and when the synchronization is not established within several tens of seconds being the second prescribed time Y1, Y2, limit, the synchronization establishment is stopped so as to surely conduct synchronization establishment for the radio channel in the case of soft hand-over.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a code division multiple access (hereinafter abbreviated as CDMA) mobile communication system for establishing a CDMA mobile communication system for establishing synchronization of radio lines at the time of call origination / termination connection and at soft handover. The present invention relates to a synchronization establishing method, a base station device, and a mobile station device.

[0002]

2. Description of the Related Art In a mobile communication system, it takes time to establish synchronization of a wireless line, and communication may be interrupted during the synchronization establishment time. If it takes a long time to establish the synchronization, it means that the user is incapable of making a call-disabled time, which is unacceptable in terms of serviceability. Therefore, a synchronization establishment waiting timer is provided to monitor the synchronization establishment time of the wireless line. Even if this timer expires, if synchronization cannot be established, the synchronization establishment process is stopped and the call termination process or handover process is immediately performed. I'm trying to suspend it.

In conventional mobile communication systems other than CDMA, the same synchronization establishment waiting timer is used to monitor the synchronization establishment time of the wireless channel in the wireless channel setting at the time of outgoing / incoming connection and the wireless channel setting at the time of handover. Then
The time of the timer is set to about several seconds, and when the synchronization establishment of the wireless line is not completed within the several seconds, the synchronization establishment process is stopped and the call termination process or the handover process is immediately interrupted.

By the way, in soft handover in a CDMA mobile communication system, since the soft handover source radio line is maintained, communication is maintained even when the soft handover destination radio line cannot establish synchronization, and in view of serviceability, a synchronization establishment waiting timer. Need not be short.

Further, in the soft handover of the CDMA mobile communication system, it takes a long time to establish synchronization of the soft handover destination radio line due to its transmission power control. Further details will be described with reference to FIG.

[0006] FIG. 5 shows a desired wave reception level and an interference wave reception level at each base station when transmission is performed at a constant maximum transmission power without transmission power control and before transmission power control is performed. FIG. 6 is a diagram showing an example of a time variation of a reception SIR which is a ratio of In the figure, first, consider a case where the base station 1 is in communication and the diversity handover is activated for the base station 2.
When the transmission power control is performed, as shown in the lower part of the figure, the reception SIR of the base station 1 is always maintained at the reference SIR, so the reception SIR of the base station 2 is the difference of the reception SIR from the base station 1. Only will vary with respect to the reference SIR.

When diversity handover is activated in such an environment, the reception SIR of the base station 2 is the reference S.
If the IR is significantly degraded, it is impossible to execute the synchronization establishment. If the reception SIR of the base station 2 is maintained in a good state with respect to the reference SIR, synchronization establishment can be completed. However, the synchronization establishment process needs to go through the steps of chip synchronization to frame synchronization.
If the reception SIR cannot be maintained in a good state during the series of processes, the synchronization establishment fails. On the other hand, it is unlikely that a good state can be maintained during this period due to changes in the radio environment due to the movement of the mobile station, especially instantaneous changes. Due to the above situation, it takes time to establish synchronization of the uplink communication channel at the soft handover destination base station during transmission power control.

Therefore, like the conventional mobile communication system described above, when a synchronization establishment waiting timer for several seconds, which is the same as at the time of outgoing / incoming connection, is used as the synchronization establishment waiting timer at the time of soft handover, the timer expires and the software waits. It will frequently happen that the handover process is interrupted.

[0009]

As described above, when the same synchronization establishment waiting timer of several seconds is used during outgoing / incoming connection and during soft handover, it does not affect the communication quality. The soft handover process may be frequently interrupted within a few seconds, which makes it difficult to execute the soft handover.

The present invention has been made in view of the above,
The purpose of the CDM is to set a long timer for waiting for synchronization establishment during soft handover so that the radio channel synchronization can be reliably established during soft handover.
(A) A method for establishing synchronization in a mobile communication system, and a base station device and a mobile station device.

[0011]

In order to achieve the above object, the present invention according to claim 1 discriminates whether a mobile station and a base station are wireless line settings associated with outgoing / incoming connection or wireless line settings associated with soft handover. However, in the case of the wireless line setting associated with the outgoing / incoming connection, the synchronization of the wireless line is established within the first predetermined time period, and if the synchronization is not established within the first predetermined time period, the synchronization is established. When the establishment of the wireless line is stopped and the wireless line is set up due to the soft handover, synchronization of the wireless line is established within the second predetermined time period longer than the first predetermined time period, and the second predetermined time period is set. The gist is to cancel the synchronization establishment if the synchronization establishment is not performed within this time.

According to the first aspect of the present invention, when a wireless line is set up for outgoing / incoming connection, synchronization of the wireless line is established within a first predetermined time period, and synchronization is established within a first predetermined time period. Is not performed, the synchronization establishment is stopped, and when the wireless line is set up due to the soft handover, the wireless line synchronization is established within the second predetermined time period longer than the first predetermined time period, and the second predetermined time period is established. If the synchronization is not established within the time limit, the synchronization establishment is stopped so that the synchronization of the wireless line at the time of soft handover can be surely established.

The present invention according to claim 2 provides the invention according to claim 1.
In the invention described above, the gist is that the first predetermined time period is about several seconds and the second predetermined time period is about several tens of seconds.

According to the second aspect of the present invention, the second predetermined time period, which is a waiting period for establishing synchronization of the wireless line at the time of soft handover, is set as long as several tens of seconds, and the wireless line at the time of soft handover is set. The synchronization can be surely established.

Further, the present invention according to claim 3 is involved in originating and terminating connection based on a call origination request signal from a mobile station, an incoming call request signal from an upper station, and a soft handover activation notification signal from a soft handover source base station. An identifying means for identifying whether the wireless line is set up or a wireless line set up due to soft handover, and is started when the identifying part identifies the wireless line set up for incoming and outgoing connection, and a first predetermined time period is set. A first timer for counting, and a second timer which is activated when the identification means identifies the wireless line setting associated with the soft handover and which counts a second predetermined time period longer than the first predetermined time period. In the case of setting the timer of No. 2 and the wireless line setting associated with the outgoing / incoming connection, the wireless line synchronization is established within the first predetermined time period, and the wireless line setting associated with the soft handover is set. In such a case, the wireless line synchronization is established within the second predetermined time period, and if the synchronization is not established within the first and second predetermined time periods, the synchronization establishment is stopped. It has as a gist to have a control means to operate.

According to the third aspect of the present invention, the first timer is activated in the wireless channel setting associated with the outgoing / incoming connection, and the second timer is activated in the wireless channel configuration associated with the soft handover. Wireless synchronization is established within the time limit of, and if the synchronization is not established within each time period, the synchronization establishment is stopped, and the soft handover is set by setting a longer second timer period during soft handover. It is possible to reliably establish the synchronization of the wireless line at the time.

According to a fourth aspect of the present invention, in the invention according to the third aspect, the first predetermined time period is about several seconds and the second predetermined time period is about several tens seconds. And

According to another aspect of the present invention, the second predetermined time period, which is a waiting period for establishing synchronization of the wireless line at the time of soft handover, is set as long as several tens of seconds, and the wireless line at the time of soft handover is set. The synchronization can be surely established.

According to the present invention of claim 5, an identifying means is provided for identifying whether the wireless line setting is associated with an outgoing / incoming call connection or the wireless line setting is associated with a soft handover, and the wireless line associated with the outgoing / incoming call connection by the identifying means. The first timer is started when it is identified as a setting, and a first timer that counts a first predetermined time period, and is started when it is identified by the identifying means as a wireless line setting associated with soft handover, A second timer that counts a second predetermined time period that is longer than the first predetermined time period, and in the case of a wireless line setting associated with an outgoing / incoming connection, establishes synchronization of the wireless line within the first predetermined time period. In the case of the wireless line setting accompanying the soft handover, the wireless line synchronization is established within the second predetermined time period, and the synchronization is not established within the first and second predetermined time periods. To And summarized in that a control means for controlling to stop the synchronization establishment.

According to the fifth aspect of the present invention, the first timer is activated in the wireless channel setting associated with the outgoing / incoming connection, and the second timer is activated in the wireless channel configuration associated with the soft handover, and each timer is activated. Wireless synchronization is established within the time limit of, and if the synchronization is not established within each time period, the synchronization establishment is stopped, and the soft handover is set by setting a longer second timer period during soft handover. It is possible to reliably establish the synchronization of the wireless line at the time.

Further, the present invention according to claim 6 provides the invention according to claim 5.
In the invention described above, the gist is that the first predetermined time period is about several seconds and the second predetermined time period is about several tens of seconds.

In a sixth aspect of the present invention, the second predetermined time period, which is a waiting period for establishing synchronization of the wireless line at the time of soft handover, is set as long as several tens of seconds, and the wireless line at the time of soft handover is set. The synchronization can be surely established.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 are block diagrams showing configurations of a base station and a mobile station, respectively, for implementing a synchronization establishing method in a CDMA mobile communication system according to an embodiment of the present invention.

The base station shown in FIG. 1 has an antenna 1 for receiving a radio signal from a mobile station and transmitting a radio signal to the mobile station. The signal received by the antenna 1 from the mobile station is transmitted and received. The signal is supplied to the demodulation circuit 7 via the distribution circuit 3 and the reception circuit 5, where synchronization is established, and despreading using a spreading code and normal demodulation are performed.
The demodulated signal is supplied to the decoding circuit 9, the transmission signal and the control signal are decoded, the control signal is supplied to the control circuit 11, and the transmission signal is transmitted to the upper station via the wire line transmission circuit 13. It Further, the transmission signal from the upper station is received by the wired line receiving circuit 15, decomposed into a control signal and a transmission signal, the control signal is supplied to the control circuit 11, and the transmission signal is encoded together with the control signal from the control circuit 11. Circuit 17
After being coded by, the modulation circuit 19 performs primary modulation and spread modulation using a spreading code, and then is transmitted from the antenna 1 to the mobile station via the transmission circuit 21 and the transmission / reception distribution circuit 3.

Further, the control circuit 11 receives the call origination request signal received from the mobile station, the call arrival request signal received from the upper station via the wired line receiving circuit 15, and the software received from the soft handover source base station via the higher station. The control circuit 11 has a discrimination function for discriminating between the wireless line setting associated with the outgoing / incoming connection or the wireless line configuration associated with the soft handover based on the handover start notification signal.
The timer 23 and the second timer 25 are connected.

The first timer 23 is activated when the identification function of the control circuit 11 identifies that the wireless line setting is associated with the outgoing / incoming connection, and the wireless line synchronization is established in the wireless line setting during the outgoing / incoming connection. It is a timer for counting a first predetermined time period, for example, a few seconds, which is a synchronization establishment waiting time period for monitoring time. Further, the second timer 25 is activated when the identification function of the control circuit 11 identifies that the wireless channel setting is associated with the soft handover, and monitors the wireless channel synchronization establishment time in the wireless channel setting during the handover. A timer for counting a second predetermined time period, for example, several tens of seconds, which is a time period for waiting for synchronization establishment.

The mobile station apparatus shown in FIG. 2 has an antenna 31 for receiving a radio signal from a base station and transmitting a radio signal to the base station. The signal received by the antenna 31 from the base station is The signal is supplied to the demodulation circuit 37 via the transmission / reception distribution circuit 33 and the reception circuit 35, where synchronization is established, and despreading using a spreading code and normal demodulation are performed. The demodulated signal is supplied to the decoding circuit 39, the transmission signal and the control signal are decoded, the control signal is supplied to the control circuit 41, and the transmission signal is supplied to the man-machine interface.

A transmission signal such as a voice signal from the man-machine interface is controlled by the encoding circuit 45 by the control circuit 41.
The signal is coded together with the control signal from, and the modulation circuit 47 performs primary modulation and spread modulation with a spreading code, and then is transmitted from the antenna 31 to the base station via the transmission circuit 49 and the transmission / reception distribution circuit 33.

Further, the control circuit 41 sets the radio line associated with the outgoing / incoming connection based on the incoming call request signal from the base station, the outgoing call request signal from the man-machine interface, and the soft handover transition determination information, or the radio associated with the soft handover. A first timer 53 and a second timer 55 are connected to the control circuit 41 while having an identification function of identifying whether the line is set.

The first timer 53 is activated when the identification function of the control circuit 41 identifies that the wireless line setting is associated with the outgoing / incoming connection, and the wireless line synchronization is established in the wireless line setting during the outgoing / incoming connection. It is a timer for counting a first predetermined time period, for example, a few seconds, which is a synchronization establishment waiting time period for monitoring time. Further, the second timer 55 is activated when the identification function of the control circuit 41 identifies that the wireless channel setting is associated with the soft handover, and monitors the wireless channel synchronization establishment time in the wireless channel setting during the handover. A timer for counting a second predetermined time period, for example, several tens of seconds, which is a time period for waiting for synchronization establishment.

In the CDMA mobile communication system configured as described above, the base station apparatus and the mobile station apparatus perform radio line setting for incoming / outgoing connection or soft handover when establishing radio channel synchronization. It is identified whether or not it is a wireless line setting, and in the case of the wireless line setting associated with the outgoing / incoming connection, the first timers 23 and 53 are started, and the wireless line is set within a few seconds which is the first predetermined time period of this timer. The synchronization is established, and if the synchronization is not established within a few seconds, which is the first predetermined time period, the synchronization is canceled,
As a result, when the call disabled time is shortened, and when it is identified that the wireless line is set up due to the soft handover, the second timers 25 and 55 are started, and the second predetermined time limit of this timer is set. The wireless line synchronization is established within a certain tens of seconds, and the synchronization is controlled to be stopped if the synchronization is not established within the second predetermined time period of a few tens of seconds.

As a result of such control, in consideration of serviceability at the time of call origination / termination connection, when synchronization cannot be established, the call is terminated in a few seconds, and during soft handover, the timer is set to several tens of seconds to the extent that synchronization can be established. By making the synchronization establishment waiting time long, it is possible to wait for the quality of the soft handover destination wireless line to be restored, and the problem that it is difficult to perform soft handover is avoided. At the time of soft handover, there is no problem in terms of serviceability because a call can be made on the soft handover source wireless line even if a long synchronization establishment waiting timer is used.

Next, with reference to FIG. 3, a call origination connection operation from the mobile station will be described.

In FIG. 3, when the mobile station transmits a call origination request signal to the base station, the base station selects a spreading code and frequency to be used in response to the call origination request signal, and a synchronization establishment wait timer of several seconds is used. The first timer 23 having the predetermined time period X1 of 1 is selected to start transmission of the downlink radio channel to the mobile station, and the first timer 23 of the time period X1 is selected.
Start Further, the base station transmits a radio channel designation signal to the mobile station to notify the spread code and frequency to be used.

When the mobile station receives the radio channel designation signal, it selects the first timer 53 having the first predetermined time period X2 of several seconds as the synchronization establishment waiting timer, and starts the downlink radio channel synchronization establishment process. , Activates the selected first timer 53. When the synchronization establishment of the downlink wireless channel is completed before the first timer 53 expires, the uplink wireless channel is transmitted. If the synchronization establishment of the wireless line is not completed before the expiration of the first timer 53, that is, within a time period of several seconds, the synchronization establishment process is stopped and the call termination process is performed.

The base station performs the process of establishing synchronization of the uplink radio line from the mobile station, and if the synchronization is established before the expiration of the first timer 23, the base station starts communication with the mobile station. If the synchronization establishment of the wireless line is not completed before the expiration of the first timer 23, that is, within a time period of several seconds, the synchronization establishment process is stopped and the call termination process is immediately performed.

Although the above-mentioned processing is the outgoing call connection processing from the mobile station, in the case of the incoming call connection processing to the mobile station, instead of sending the first outgoing call request signal of the above processing, the incoming call request from the upper station is received. A signal is sent to the base station, which in response sends an incoming signal to the mobile station. Then, the only difference is that the mobile station returns an incoming call response signal to the base station, and thereafter, the base station responds to this incoming call response signal in the same manner as the processing of FIG. A first timer 2 which selects a spreading code and frequency to be used and has a first predetermined time period X1 of several seconds as a synchronization establishment waiting timer.
The same applies to the case where 3 is selected.

Next, the operation at the time of soft handover will be described with reference to FIG.

In FIG. 4, when the mobile station transmits the cell transfer determination information to the soft handover source base station, the soft handover source base station notifies the soft handover destination base station of a soft handover activation notification. The soft handover destination base station selects the spreading code and frequency to be used in response to the soft handover activation notification, and
Second predetermined time Y of several tens of seconds as a synchronization establishment waiting timer
Select the second timer 25 with 1. Then, the soft handover destination base station transmits the downlink radio channel to the mobile station, starts the synchronization establishing process, and activates the second timer 25 of the time period Y1. Also, the soft handover destination base station sends a radio channel designation signal to the soft handover source base station to notify the spreading code and frequency to be used.

The soft handover source base station transfers the radio line designation signal to the mobile station. When the mobile station receives the radio line designation signal, the mobile station selects the second timer 55 having the second predetermined time period Y2 of several tens of seconds as the synchronization establishment waiting timer, and starts the downlink radio line synchronization establishment process, The selected second timer 55 is started. When the synchronization establishment of the downlink radio channel is completed before the second timer 55 expires, the uplink radio channel is transmitted to the soft handover destination base station.
If the synchronization establishment of the wireless line is not completed before the second timer 55 expires, that is, within a time period of several tens of seconds, the synchronization establishment process is stopped and the call termination process is performed.

The soft handover destination base station performs the process of establishing synchronization of the uplink radio line from the mobile station, and if the synchronization establishment is completed before the expiration of the second timer 25, the soft handover destination base station determines that it is the mobile station. When communication is started, but the synchronization establishment of the wireless line is not completed before the expiration of the second timer 25, that is, within a time period of several tens of seconds, the synchronization establishment process is stopped and the call termination process is immediately performed.

[0043]

As described above, according to the present invention,
When synchronization is not established within the first predetermined time period when the wireless line is set up for outgoing / incoming connection, the synchronization is stopped, and when the wireless line is set up for soft handover, the first line is set up.
Since the wireless line synchronization is established within the second predetermined time period longer than the predetermined time period, the synchronization is canceled when the synchronization is not established within the second predetermined time period.
It is possible to reliably establish the synchronization of the wireless line at the time of soft handover. That is, in consideration of serviceability at the time of call origination / termination connection, if the synchronization cannot be established, the call is terminated in a relatively short first predetermined time period of a few seconds, and at the time of soft handover, a relatively long period such that the synchronization can be established. 2, the synchronization establishment waiting time of the timer is lengthened to several tens of seconds, which is a predetermined time period, to wait for the quality of the soft handover destination wireless line to be restored, and to avoid the problem that it is difficult to perform soft handover.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a base station that implements a synchronization establishing method in a CDMA mobile communication system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a mobile station that implements a synchronization establishing method in a CDMA mobile communication system according to an embodiment of the present invention.

FIG. 3 is a sequence diagram showing a transmission connection operation by the base station and mobile station shown in FIGS.

FIG. 4 is a sequence diagram showing operations during soft handover by the base station and mobile station shown in FIGS.

FIG. 5 is a reception S at each base station when transmission is performed with a constant maximum transmission power without performing transmission power control before execution of diversity handover and when transmission power control is performed.
It is a figure which shows the time variation example of IR.

[Explanation of symbols]

 7 Base Station Demodulation Circuit 9 Base Station Decoding Circuit 11 Base Station Control Circuit 23 Base Station First Timer 25 Base Station Second Timer 37 Mobile Station Demodulation Circuit 39 Mobile Station Decoding Circuit 41 Move Control circuit of station 53 First timer of mobile station 55 Second timer of mobile station

Claims (6)

[Claims] 1. A mobile station and a base station discriminate between a wireless line setting associated with an outgoing / incoming connection or a wireless line configuration associated with a soft handover, and in the case of a wireless line configuration associated with an outgoing / incoming connection, a first predetermined time period. If the synchronization is not established within the first predetermined time period, the synchronization is stopped within the first predetermined time period, and the synchronization establishment is stopped. The wireless line synchronization is established within a second predetermined time period longer than the predetermined time period, and the synchronization establishment is stopped when the synchronization is not established within the second predetermined time period. A method for establishing synchronization in a CDMA mobile communication system. 2. The method for establishing synchronization in a CDMA mobile communication system according to claim 1, wherein the first predetermined time period is about several seconds and the second predetermined time period is about several tens of seconds. . 3. A radio line setting associated with an outgoing / incoming connection based on a call origination request signal from a mobile station, an incoming call request signal from an upper station, and a soft handover activation notification signal from a soft handover source base station, or accompanying soft handover. An identifying unit for identifying whether or not the wireless line is set up; a first timer that is activated when the identifying unit identifies the wireless line for the incoming / outgoing connection, and counts a first predetermined time period; A second timer which is activated when the identification means identifies a wireless line setting associated with a soft handover, and which counts a second predetermined time period longer than the first predetermined time period, and an outgoing / incoming connection. In the case of the wireless line setting accompanying it, the wireless line synchronization is established within the first predetermined time period, and in the case of the wireless line setting accompanying the soft handover, the second predetermined time period is established. A wireless line synchronization is established within a time limit, and a control means for controlling the synchronization establishment to be stopped when the synchronization is not established within the first and second predetermined time periods. A base station device in a CDMA mobile communication system. 4. The base station apparatus in a CDMA mobile communication system according to claim 3, wherein the first predetermined time period is about several seconds and the second predetermined time period is about several tens of seconds. . 5. Identification means for identifying whether the wireless line setting is associated with an outgoing / incoming call connection or the wireless line setting is associated with a soft handover, and when the identifying means identifies the wireless line setting associated with an outgoing / incoming call connection. A first timer that is activated and counts a first predetermined time period, and is activated when the identification unit identifies that the wireless line setting is associated with a soft handover, and is longer than the first predetermined time period. A second timer for counting a second predetermined time period and a wireless line for soft handover when the synchronization of the wireless line is established within the first predetermined time period in the case of setting a wireless line for outgoing / incoming connection. In the case of setting, the wireless line synchronization is established within the second predetermined time period, and the synchronization establishment is stopped if the synchronization is not established within the first and second predetermined time periods. Control A mobile station device in a CDMA mobile communication system, comprising: 6. The mobile station apparatus in a CDMA mobile communication system according to claim 5, wherein the first predetermined time period is about several seconds, and the second predetermined time period is about several tens of seconds. .