JP2000354271A - Mobile communication system and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid a high-speed individual packet channel from being set which provides large interference between a radio base station and a mobile station at a great distance from the radio base station. SOLUTION: A propagation delay time measurement means 115 of a radio base station 102 measures a propagation delay time in the case of receiving a random access signal from a mobile station 101, a control station 103 discriminates a maximum transmission rate corresponding to a propagation delay time measured by a propagation delay time measurement means 118, a symbol rate setting means 119 sets a symbol rate that can be assigned to the maximum transmission rate, and a radio channel control means 117 gives an instruction to set an individual packet channel at a transmission rate in response to the symbol rate between the mobile station 10 and the radio base station 102.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a CDMA (Code Division Multiple Acceses) radio access system in mobile communication using an automobile telephone and a portable telephone.
s) A mobile communication system and method to which the scheme is applied.

[0002]

2. Description of the Related Art Conventionally, as a mobile communication system and method, there is one disclosed in Japanese Patent Application Laid-Open No. 10-13937.

[0003] In a mobile communication system, a mobile station and a radio base station transmit and receive control data, user data, and the like via a radio channel. When a mobile station transmits control data including an outgoing request to a network including a radio base station and a control station or responds to an incoming call from a radio base station, a random access channel commonly used by a plurality of users. It is common to use a common physical channel called.

In IMT-2000, a high-speed packet service will be provided as a non-voice data communication service. In the high-speed packet service, an individual packet channel using an individual radio channel for each mobile station is applied.

In a CDMA mobile communication system,
Suitable for accommodating various services from low rate to high rate. This is because the spread CDMA signal can be multiplexed and transmitted in the radio section by selecting a physical channel having a symbol rate that can accommodate the rate required by each service.

At this time, since a physical channel for transmitting data with a high symbol rate has a low spreading factor, the physical channel transmits at a higher transmission power than a physical channel for transmitting a voice signal or the like with a low symbol rate.

In a CDMA mobile communication system, the number of channels that can be accommodated in each cell is determined by the total amount of interference in that cell. Less than for lower rate physical channels.

[0008] The packet service is characterized in that the transmission rate varies with time according to the amount of information to be transmitted.
In addition, the peak speed of the uplink and the downlink is different, and asymmetric communication is generally performed in which the peak speed of the downlink is higher than the peak speed of the uplink.

[0009] Of the conventional configurations in a CDMA mobile communication system, those related to individual packet channel communication are shown in FIG. 5 and will be described. FIG. 5 is a block diagram showing a configuration of a conventional mobile communication system.

The mobile communication system shown in FIG. 5 includes a mobile station 501, a radio base station 502, and a control station 503.

The radio base station 502 transmits and receives the spread baseband signal in a radio section.
And the radio base station 502 according to the instruction from the control station 503.
A base station control unit 505 for controlling the whole; a random access channel receiving unit 506 for receiving a random access channel; and first to n-th dedicated channel transmitting / receiving units 507 to 507 for performing baseband signal processing on a dedicated control channel or a dedicated packet channel. 509 and a control station transmitting / receiving means 510 for transmitting / receiving the radio section transmission information / base station control information to / from the control station 503.

The control station 503 includes a transmission / reception means 511 for transmitting / receiving radio section transmission information / base station control information to / from the radio base station 502 and a radio channel control means 512 for controlling setting and release of a radio channel. It is provided with.

Next, an operation related to the setting of the individual packet channel of the mobile communication system having such a configuration will be described.

When the mobile station 501 requests the setting of an individual packet channel, a transmission request is first transmitted to the network using a random access channel to which control information is transmitted and user information is also transmitted in packet communication. I do. At this time, the random access channel receiving section 506 of the radio base station 502 receives the random access signal,
Send it to the control station 503.

[0015] In response, radio channel control means 512 of control station 503 instructs base station control section 505 to set an individual control channel. The base station control unit 505 selects an available resource from each of the dedicated channel transmitting / receiving units 507 to 509, and selects the selected dedicated channel transmitting / receiving unit (for example, 5
07), a link setting of the dedicated control channel is instructed.

After that, the mobile station 501 requests the network side to set a radio channel including a peak rate of packet communication on an individual control channel. Wireless channel control means 51
In 2, the base station control unit 505 is instructed to set an individual packet channel having a symbol rate corresponding to the peak rate requested by the mobile station 501.

The base station control unit 505 selects a free resource from each of the dedicated channel transmission / reception units 507 to 509, and sends the selected dedicated channel transmission / reception unit (eg, 508) the symbol specified by the radio channel control unit 512. Instruct the link setting of the individual packet channel of the rate.

In this manner, the operation related to the setting of the individual packet channel at the peak rate requested by the mobile station 501 is completed.

[0019]

However, in the conventional apparatus, when a mobile station near a cell boundary far from the radio base station is required to set up a high-speed dedicated packet channel, the radio base station is also used in this case. Since the station accepts the request, the signal of the physical channel of the high symbol rate with a small spreading factor is transmitted with a large transmission power, and there is a problem that the amount of interference in the cell increases.

Since the individual packet channel generally has a higher downlink rate, an increase in the amount of downlink interference is a problem.

The present invention has been made in view of such a point, and can avoid setting a high-speed dedicated packet channel that causes large interference with a mobile station that is far from a radio base station. It is an object to provide a mobile communication system and method.

[0022]

According to the present invention, a radio base station measures a propagation delay time when a random access signal is received from a mobile station, and a control station determines a maximum propagation delay time corresponding to the measured propagation delay time. Is determined, a symbol rate that can be assigned to the maximum transmission rate is set, and an instruction to set an individual packet channel at a transmission rate corresponding to the symbol rate between the mobile station and the radio base station is performed.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first aspect of the present invention provides a CDMA
The system is applied, the base station apparatus, comprises a first measuring means for measuring the propagation delay time when receiving a random access signal from the mobile station apparatus, the control station apparatus, the measured propagation delay time Determining means for determining a corresponding maximum transmission rate, setting means for setting a symbol rate that can be assigned to the maximum transmission rate, and an individual packet channel at a transmission rate according to the symbol rate, And a first control unit that issues an instruction to be set between the base station apparatuses.

According to this configuration, it is possible to avoid an increase in the amount of intra-cell interference caused by setting a high-speed dedicated packet channel for a mobile station device far from the base station device.

According to a second aspect of the present invention, in the first aspect, the base station apparatus periodically measures the propagation delay time during communication of the dedicated packet channel set by the instruction of the first control means. (2) A configuration is provided in which two control means are provided, and the control station apparatus switches to a symbol rate corresponding to the measured propagation delay time.

According to this configuration, even after setting the individual packet channel, it is possible to change to the maximum packet transmission rate according to the distance between the mobile station device and the base station device.

According to a third aspect of the present invention, in the second aspect, the base station apparatus transmits the propagation delay time measured by the second measuring means to the second measuring means in accordance with the previous and present fluctuations. A configuration including second control means for updating the measurement cycle of the propagation delay time is employed.

According to this configuration, it is possible for a mobile station apparatus having a high moving speed to follow a change in distance from the base station apparatus.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the first and second measuring means include:
A first threshold for determining an effective received signal other than a noise component, and a second threshold for determining an effective received power that is separated from the maximum value of the received power by a predetermined value; A configuration is adopted in which the direct wave is estimated by comparing the two thresholds with the received signal to measure the propagation delay time.

According to this configuration, even if the received power of the delayed wave is larger than that of the direct wave in a multipath environment,
The propagation delay time can be correctly measured.

According to a fifth aspect of the present invention, when an individual packet channel is set in a mobile station device, the base station device measures a propagation delay time when receiving a random access signal from the mobile station device. The control station device determines a symbol rate of a wireless channel between the mobile station device and the base station device according to the measurement result.

According to this method, it is possible to avoid an increase in the amount of intra-cell interference caused by setting a high-speed dedicated packet channel for a mobile station apparatus far from the base station apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of a mobile communication system according to Embodiment 1 of the present invention.

The mobile communication system shown in FIG. 1 includes a mobile station 101, a radio base station 102, and a control station 103.

The radio base station 102 transmits and receives the spread baseband signal in a radio section.
And the radio base station 102 according to the instruction from the control station 103.
A base station control unit 105 for controlling the whole, a random access channel receiving unit 106 for receiving a random access channel, and first to n-th dedicated channel transmitting and receiving units 107 to 107 for performing baseband signal processing on dedicated control channels and dedicated packet channels. 109, and a control station transmitting / receiving means 110 for transmitting / receiving the radio section transmission information / base station control information to / from the control station 103.

Random access channel receiving section 106
Is a delay profile generating means 111 for generating delay profile data, a path search means 112 for analyzing the delay profile data and selecting a path effective for the RAKE reception processing, and a RAKE for the path selected by the path search means 112. RAKE receiving means 11 for performing reception processing
3, channel decoding means 114 for performing radio frame decomposition processing and decoding processing for error detection and error correction on the reception data output by the rake reception processing, and a delay profile output from the delay profile generation means 111 And a propagation delay time measuring means 115 for measuring a propagation delay time for the path selected by the path search means 112 from the data.

The control station 103 transmits and receives radio section transmission information / base station control information to and from the radio base station 102 to and from the base station, a radio channel control means 117 to control setting and release of a radio channel, Based on the propagation delay time measurement result from the propagation delay time measurement means 115,
Propagation delay time determining means 118 for determining the maximum value of the packet transmission rate that can be allocated to mobile station 101, and assignable to mobile station 101 based on the maximum value of the transmission rate from propagation delay time determining means 118 And a symbol rate setting unit 119 for obtaining a symbol rate and notifying the wireless channel control unit 117 of the symbol rate.

The operation of the mobile communication system according to the first embodiment thus configured will be described.

When a request for setting an individual packet channel is made from the mobile station 101, an outgoing call request is first transmitted to the network using a random access channel. At this time,
Random access channel receiving section 1 of wireless base station 102
06 receives the random access signal, and the control station transmitting / receiving means 110 sends the received signal to the control station 103.

The operation of the random access channel receiving section 106 when receiving this random access channel will be described.

In the random access channel in the CDMA mobile communication system, the radio base station 102 can easily acquire the initial synchronization of the burst reception.
A method is known in which the mobile station 101 spreads the spread code phase in synchronization with the frame timing synchronized with the radio base station 102, and transmits the spread burst signal.

In such a method, when an uplink burst signal is transmitted such that the random access timing of mobile station 101 is synchronized with the frame timing of radio base station 102, delay profile generating means 111 of random access channel receiving section 106 The delay profile data is generated by calculating the correlation between the spreading code used in the random access channel and the CDMA reception signal from the wireless transmission / reception means 104 while shifting the phase.

The path search means 112 selects a path effective for RAKE reception from the delay profile data output from the delay profile generation means 111,
The selected path is instructed to the RAKE receiving means 113. At this time, a method of selecting a reception path having a large reception power can be considered.

Propagation delay time measurement means 115 measures the propagation delay time of the path selected by path search means 112 from the delay profile data from delay profile generation means 111, and compares this measurement result with control station transmission / reception means 110.
To the control station 103 via the.

As a method of measuring the propagation delay time, the phase shift from the frame timing of the radio base station 102 is measured for the plurality of paths selected by the path search means 112 having the highest received power, so that the path is measured. Station 1
01 and the wireless base station 102 can be measured.

The RAKE receiving means includes a path search means 11
2 for each of the plurality of reception paths indicated by
After performing the despreading process and the synchronous detection process, the maximum ratio combining in which each synchronous detection output is weighted is performed.

The channel decoding means 114
The soft decision data from the receiving unit 113 is subjected to radio frame format decomposition processing, decoding processing for error detection / correction, and the like.

Radio channel control means 11 of control station 103
7 instructs the base station control unit 105 to set an individual control channel. The base station control unit 105 selects a free resource from the dedicated channel transmitting / receiving units 107 to 109, and instructs the selected dedicated channel transmitting / receiving unit (for example, 107) to set a link of the dedicated control channel.

The propagation delay time determining means 118 obtains the maximum value of the packet transmission rate that can be assigned to the mobile station 101 based on the result of the propagation delay time measurement from the propagation delay time measuring means 115.

As a method of obtaining the maximum value of the transmission rate, a method in which the propagation delay time judging means 118 has a table which previously associates the maximum assignable transmission rate with the propagation delay time can be considered.

The symbol rate setting means 119 obtains a symbol rate that can be assigned to the mobile station 101 based on the maximum value of the transmission rate from the propagation delay time determining means 118, and notifies the radio channel control means 117.

Thereafter, the mobile station 101 requests the network side to set a wireless channel including a peak rate of packet communication on an individual control channel.

The radio channel control means 117
Symbol rate S according to peak rate required by 01
0 and the symbol rate Smax notified from the symbol rate setting means 119, and if S0 does not exceed Smax, the base station control unit 105 is instructed to set an individual packet channel of the symbol rate S0. .

The base station control unit 105 selects a free resource from each of the dedicated channel transmitting / receiving units 107 to 109, and sends the selected dedicated channel transmitting / receiving unit (eg, 108) the symbol designated by the radio channel control unit 117. The link setting of the individual packet channel of the rate S0 is instructed.

If S0 exceeds Smax, the base station control unit 105 is instructed to set a dedicated packet channel of the symbol rate Smax, and the transmission to the mobile station 101 is performed according to the symbol rate Smax. It instructs via the radio base station 102 to set a dedicated packet channel at the rate.

The base station control unit 105 selects a free resource from each of the dedicated channel transmission / reception units 107 to 109, and sends the selected dedicated channel transmission / reception unit (for example, 109) the symbol specified by the radio channel control unit 117. The link setting of the individual packet channel of the rate Smax is instructed.

In this way, the operation related to the individual packet channel setting with the mobile station 101 is completed.

As described above, according to the mobile communication system of the first embodiment, based on the result of measuring the propagation delay time when receiving the random access channel from mobile station 101,
By controlling to set a transmission rate individual packet channel within a settable range, the radio base station 102
It is possible to avoid setting a high-speed dedicated packet channel that causes large interference with the mobile station 101 far from the mobile station 101.

(Embodiment 2) FIG. 2 is a block diagram showing a configuration of an individual channel transmitting / receiving section provided in a radio base station of a mobile communication system according to Embodiment 2 of the present invention.

The individual packet channel transmitting / receiving section 201 shown in FIG. 2 is used in place of each of the individual channel transmitting / receiving sections 107 to 109 shown in FIG. 1 described in the first embodiment. A profile generation unit 202, a path search unit 203 that analyzes delay profile data and selects a valid path for a RAKE reception process, a RAKE reception unit 204 that performs a RAKE reception process on the path selected by the path search unit 203, , Channel decoding means 20 for performing radio frame decomposition processing and decoding processing for error detection and error correction on the received data output from the RAKE receiving means 204.
5, propagation delay time measuring means 206 for measuring the propagation delay time for the path selected by path search means 203 from the delay profile data output from delay profile generating means 202, and propagation delay time measuring means 206. , A propagation delay time measurement timer 207 that timer-controls a measurement cycle, a channel encoding unit 208 that performs a radio frame assembling process and an encoding process for error detection and error correction, and a transmission data from the channel encoding unit 208. Data modulation means 209 for performing data modulation;
And a spreading means 210 for spreading transmission data from the data modulation means 209 by a spreading code.

The individual packet channel transmitting / receiving unit 2 in the radio base station of the mobile communication system thus configured
01 will be described.

However, since the operation up to the setting of the individual packet channel is the same as that described in the first embodiment, here, the operation relating to the measurement of the propagation delay time in the individual packet channel transmitting / receiving section 201 after the setting of the individual packet channel is performed. Will be described.

As a dedicated channel in a CDMA mobile communication system, a method is known in which a radio base station 102 spreads a perch channel to a perch channel, which is constantly transmitted downward, with a spreading code phase, and transmits an uplink signal. .

In this method, when the uplink packet data of mobile station 101 is transmitted, delay profile generating means 202 of dedicated packet channel transmitting / receiving section 201
Generates delay profile data by calculating the correlation between the spreading code used in the dedicated packet channel and the CDMA reception signal from the wireless transmission / reception means while shifting the phase.

The path search means 203 selects a path effective for RAKE reception from the delay profile data output from the delay profile generation means 202,
The selected path is instructed to the rake receiving means 204. At this time, a method of selecting a reception path having a large reception power can be considered.

Propagation delay time measurement means 206 measures the propagation delay time of the path selected by path search means 203 from the delay profile data output from delay profile generation means 202, and compares the measurement result with control station transmission / reception means 1.
Notify the control station via 10.

The propagation delay time measurement means 206 executes the measurement and notifies the control station 103 of the measurement result. The propagation delay time measurement timer 207 controls the preset measurement execution cycle by timer, and performs the measurement. This is the timing when execution is instructed.

The propagation delay time is measured by measuring the phase shift from the frame timing of the radio base station 102 for the plurality of paths selected by the path search means 203 having the highest received power. Station 1
01 and the wireless base station 102 can be measured.

In the control station 103, the propagation delay time measurement result from the dedicated packet channel transmitting / receiving section 201 provided in the radio base station 102 is larger than the maximum packet transmission rate that can be assigned based on the propagation delay time measurement result at random access. , If it is larger, the mobile station 101
, The update of the maximum packet transmission rate is notified, and the packet transmission rate and the symbol rate are changed as necessary.

On the other hand, if the maximum packet transmission rate is smaller than the maximum assignable packet transmission rate based on the result of the propagation delay measurement at the time of random access, the mobile station 101 is notified of the decrease in the maximum packet transmission rate. Then, the packet transmission rate and the symbol rate are changed.

In this way, the operation for updating the maximum packet transmission rate after setting the individual packet channel with the mobile station 101 is executed.

As described above, according to the dedicated packet channel transmitting / receiving section 201 of the second embodiment, even after setting the dedicated packet channel with the mobile station 101, the propagation delay time is periodically measured, so that the mobile station 101 Even when the distance between the mobile station 101 and the base station 102 changes, an individual packet channel with an appropriate transmission rate can be set for each mobile station 101.

(Embodiment 3) FIG.3 is a block diagram showing a configuration of an individual channel transmitting / receiving section provided in a radio base station of a mobile communication system according to Embodiment 3 of the present invention.

However, in the third embodiment shown in FIG. 3, parts corresponding to the respective parts of the second embodiment in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

The difference between individual packet channel transmitting / receiving section 301 of the third embodiment shown in FIG. 3 and individual packet channel transmitting / receiving section 201 of the second embodiment shown in FIG. For the measurement result,
Propagation delay time fluctuation measuring means 302 for measuring the amount of fluctuation of the value from the previous measurement result, and propagation delay time fluctuation measuring means 30
2, the propagation delay time measurement timer 20
Measurement period control means 30 for controlling the timer value set to 7
3 is provided.

The individual packet channel transmitting / receiving unit 3 in the radio base station of the mobile communication system thus configured
01 will be described.

However, the operation up to the setting of the individual packet channel is the same as that described in the first embodiment. Since the basic operation related to the propagation delay time measurement in individual packet channel transmitting / receiving section 301 after setting the individual packet channel is the same as that described in the second embodiment, the measurement by propagation delay time measurement timer 207 is performed here. The operation related to the cycle setting will be described.

K measured by the propagation delay time measuring means 206
The measurement result of the + 1st measurement is D (k + 1), and the variation of the propagation delay time with respect to the measurement result D (k) of the kth measurement is ΔD
(K).

The propagation delay time fluctuation measuring means 302 calculates ΔD (k−1) for the k-th measurement result D (k) and notifies the measurement cycle control means 303 of the result. The measurement cycle control unit 303 shortens the measurement cycle when △ D (k) is large, and reduces the measurement cycle when △ D (k) is small, based on the variation △ D (k) from the propagation delay time variation measurement unit 302. Sets a measurement timer value in the propagation delay time measurement timer 207 to extend the measurement cycle.

As a method of determining the measurement cycle based on the variation ΔD (k), the measurement cycle control means 303 has a table for obtaining a measurement cycle to be set for the measured variation. It is possible to consider such a method.

In this way, the operation for updating the propagation delay time measurement cycle after setting the individual packet channel is executed.

As described above, according to the dedicated packet channel transmitting / receiving section 301 of the third embodiment, when the propagation delay time is measured after setting the dedicated packet channel with the mobile station 101, the mobile station 101 having the fast moving speed can be used. On the other hand, by performing the measurement in a short cycle, it is possible to follow the mobile station 101 having a high moving speed and to set an individual packet channel having an appropriate transmission rate.

(Embodiment 4) FIG. 4 is a diagram showing measurement of propagation delay time measuring means in a random access channel receiving section or dedicated channel transmitting / receiving section provided in a radio base station of a mobile communication system according to Embodiment 4 of the present invention. It is an operation | movement flowchart regarding operation | movement.

However, the configuration of the random access channel receiving section is the same as that described in the first embodiment, and the configuration of the individual channel transmitting / receiving section is the same as that described in the second or third embodiment.

Hereinafter, the operation relating to the propagation delay time measurement in the fourth embodiment will be described with reference to FIG.

However, the delay profile data output by the delay profile generation means 111 or 202 is represented by L [0],
L [1], ..., L [p], ..., L [p_MAX]. Where L [p]
Indicates that the received power at the path phase p is L.

The propagation delay time measuring means 115 or 2
In 06, a threshold Apow1 and a threshold Adown are set. The threshold Apow1 is a power threshold for determining a noise component and a valid reception path. The threshold value Adown is used to determine how far a path having a lower received power relative to the maximum value in the delay profile data is determined to be valid.

In step ST401, each variable is initialized. At this time, Apow1 is substituted for Apow. Here, temp is a variable of received power, delay is a propagation delay time, p is a measured propagation delay time value corresponding to the path phase, flag is a propagation delay time measurement completion flag, and Apow is a power threshold.

In step ST402, p is compared with the variable p_MAX to determine whether or not it is the end data of the delay profile data. If p points to the end, the process proceeds to step ST405; otherwise, the process proceeds to step ST403.

In step ST403, L [p] and the variable temp
And if L [p] is greater than temp, step S
The process moves to T404, otherwise to step ST405.

In step ST404, L [p] is greater than temp.
Is large, substitute L [p] for temp and set the value of variable p to 1
Increment.

In step ST405, the value of the variable p is set to 1
Increment.

In step ST406, at this point, the maximum value of the received power in the delay profile data is substituted for the variable temp. A power threshold based on the maximum value of the received power is substituted into Apow2, and a variable p is initialized.

In step ST407, Apow1 and Apow2
Perform a comparison of If Apow2 is larger than Apow1, the process proceeds to step ST408, otherwise, the process proceeds to step S408.
The process moves to T409.

In step ST408, the power threshold Apow
Assign Apow2.

In step ST409, the larger of Apow1 and Apow2 is assigned to the power threshold Apow at this time. If the propagation delay time measurement completion flag flag is not 1, the measurement has not been completed, so that step ST41 is performed.
Move to 0. If the flag is 1, the measurement is completed, and the process shifts to step ST413.

In step ST410, a comparison is made between the received power L [p] at the path phase p and the power threshold Apow.
If L [p] exceeds Apow, the process proceeds to step ST411; otherwise, the process proceeds to step ST412.

In step ST411, the reception path at the path phase p is regarded as a direct wave, and the propagation delay time delay
Is substituted for p, and 1 is substituted for the measurement completion flag flag.

In step ST412, the value of the variable p is set to 1
Increment.

In step ST413, a measured propagation delay time p is output.

As described above, according to the propagation delay time measuring means of the fourth embodiment, even when the propagation delay time is measured in a multipath environment where the reception power of the delayed wave is larger than that of the direct wave, , A power threshold Apow for selecting a reception path sufficiently large with respect to a noise component, and a power threshold Adown for selecting a reception path within a certain range with respect to a reception power value of a path having a maximum reception power. As a result, the propagation delay time measurement can be performed correctly.

[0103]

As described above, according to the present invention,
It is possible to avoid an increase in the amount of intra-cell interference caused by setting a high-speed dedicated packet channel for a mobile station that is far from the radio base station.

Further, even after the individual packet channel is set, the maximum packet transmission rate can be changed according to the distance between the mobile station and the radio base station.

Further, even a mobile station having a high moving speed can follow a change in distance from a radio base station.

Further, even when the received power of the delayed wave is larger than that of the direct wave in a multipath environment, the propagation delay time can be measured correctly.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a mobile communication system according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram showing a configuration of a dedicated channel transmitting / receiving unit provided in a radio base station of the mobile communication system according to Embodiment 2 of the present invention.

FIG. 3 is a block diagram showing a configuration of a dedicated channel transmitting / receiving unit provided in a radio base station of the mobile communication system according to Embodiment 3 of the present invention.

FIG. 4 is an operation flowchart relating to a measurement operation of a propagation delay time measuring means in a random access channel receiving unit or a dedicated channel transmitting / receiving unit provided in a radio base station of a mobile communication system according to Embodiment 4 of the present invention.

FIG. 5 is a block diagram showing a configuration of a conventional mobile communication system.

[Description of Code] 101 Mobile station 102 Radio base station 103 Control station 115, 206 Propagation delay time measurement means 117 Radio channel control means 118 Propagation delay time determination means 119 Symbol rate setting means 207 Propagation delay time measurement timer 302 Propagation delay time fluctuation Measurement means 303 Measurement cycle control means

Claims (5)

[Claims] 1. A base station apparatus to which a CDMA system is applied, comprising: a first measuring means for measuring a propagation delay time when a random access signal is received from a mobile station apparatus;
In the control station device, a determining unit that determines a maximum transmission rate corresponding to the measured propagation delay time, a setting unit that sets a symbol rate that can be assigned to the maximum transmission rate, A mobile communication system, comprising: a first control unit that issues an instruction to set an individual packet channel at a transmission rate between the mobile station device and the base station device. 2. The base station apparatus further comprises a second measuring means for periodically measuring a propagation delay time during communication of the dedicated packet channel set by the instruction of the first control means, wherein the control station apparatus is provided with the second measuring means. The mobile communication system according to claim 1, wherein the switching is performed to a symbol rate corresponding to the measured propagation delay time. 3. The base station apparatus according to claim 2, wherein said second and third propagation delay times measured by said second measuring means are changed in accordance with a variation amount of said propagation delay time between said previous time and said current time.
3. The mobile communication system according to claim 2, further comprising second control means for updating a measurement cycle of said propagation delay time in said measurement means. 4. A first and a second measuring means for determining a first threshold for determining an effective received signal other than a noise component and an effective received power that is separated from a maximum value of the received power by a predetermined value. And a propagation delay time is measured by estimating a direct wave by comparing the first and second thresholds with a received signal.
The mobile communication system according to any one of the above. 5. When setting an individual packet channel in a mobile station device, a base station device measures a propagation delay time when receiving a random access signal from the mobile station device, and the control station device determines the propagation delay time. A mobile communication method comprising: determining a symbol rate of a wireless channel between the mobile station device and the base station device according to a measurement result.