JP2001346250A - Mobile communication system and its communication method, base station, and mobile station unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mobile communication system where battery consumption of mobile stations can be reduced. SOLUTION: In the mobile communication system consisting of a base station and mobile stations, in the case of transmitting a control channel with a fixed frequency at all times and transmitting speech channels with other frequency at all times, the base station transmits the control channel and the speech channels by changing respective burst lengths depending on the presence of a speech. Each mobile station detects a burst length of the speech channel assigned in advance to itself among the speech channels and reaches a reception state when detecting the presence of a speech. Since the mobile station can discriminate the presence of a speech by having only to detect the burst length of the speech channel without the need for receiving a signal of the speech channels and for analyzing the received signal, it is not required to always start a signal processing section or the like requiring much power consumption thereby the battery consumption is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication system including a base station and a plurality of mobile stations, and more particularly to a mobile communication system suitable for reducing battery consumption of a mobile station, a communication method thereof, and a base. The present invention relates to a station device and a mobile station device.

[0002]

2. Description of the Related Art In a recent society, various types of digital radio communication systems coexist, and among them, there is a mobile communication system of a fixed channel assignment type. In this mobile communication system, a mobile terminal (mobile station) side intermittently receives a communication channel transmitted from a base station when necessary, and when a carrier of the communication channel is detected, it is determined that a communication is to be started, and a call is made. The signal is received and the signal content is analyzed. That is, every time a carrier is detected, a signal processing unit or the like that consumes a large amount of power is activated to perform a receiving operation.

[0003]

[0006] Portable mobile terminals have been miniaturized, and the batteries installed in the mobile terminals have become smaller, so that there is a limit to the time that can be used continuously by one charge. For this reason, when a signal processing unit or the like that consumes a large amount of power is activated every time a carrier of a communication channel is detected as in the above-described related art, the power consumption increases and the battery is consumed in a short time. There is.

In order to solve this problem, if the intermittent reception interval is extended to reduce the number of times the signal processing unit is started, the consumption of the battery can be reduced. However, conversely, the time until carrier detection becomes long, and in a press-talk type communication system mainly including a press-talk communication having no call connection procedure, a problem of a break in talk occurs.

[0005] Further, when a state called "steal" occurs in which another mobile station temporarily uses the communication slot allocated to the own station, the own station keeps the communication until the communication by the other station is completed. It is necessary to always receive the signal of the assigned slot, analyze the signal content by operating the signal processing unit having large power consumption, and monitor the end of stealing by another station. For this reason, there is a problem that power consumption increases as the steal time becomes longer, and the battery is consumed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and a mobile communication system capable of reducing power consumption of a mobile station and reducing battery consumption, a communication method thereof, and a base. It is an object to provide a station device and a mobile station device.

[0007]

According to the present invention, first, in a mobile communication system including a base station and a plurality of mobile stations, the base station constantly transmits a control channel at a fixed frequency and simultaneously transmits the same or another control channel. In transmitting a plurality of communication channels at the same frequency at all times, the burst length of each of the control channel and the communication channel is changed according to the presence or absence of a communication, and the mobile station transmits the communication channel in advance among the plurality of communication channels in advance. Communication control means for detecting the presence of a call from the burst length of the communication channel assigned to the station and entering a receiving state is provided. As a result, the presence of a call can be detected only by determining the presence or absence of a carrier without receiving a call channel, and it is possible to reduce battery consumption.

Second, in a mobile communication system including a base station and a plurality of mobile stations, the base station constantly transmits a control channel at a fixed frequency and constantly transmits a plurality of communication channels at the same or another frequency. In doing so, transmission is performed by changing the burst length of each of the control channel and the communication channel according to the presence or absence of a call, and the mobile station is configured to transmit the burst length of the communication channel previously allocated to its own station among the plurality of communication channels. Is determined at a predetermined cycle, and communication control means for confirming the presence of a service area is provided. This makes it possible to determine the presence of a base station without receiving a control channel signal.

Third, in the second mobile communication system, the predetermined period is determined by downlink broadcast information transmitted by the base station. As a result, it is possible to determine the location of the base station without receiving a control channel signal.

Fourth, in a mobile communication system including a base station and a plurality of mobile stations, the base station constantly transmits a control channel at a fixed frequency and constantly transmits a plurality of communication channels at the same or another frequency. In doing so, transmission is performed by changing the burst length of each of the control channel and the communication channel according to the presence or absence of a call, and the mobile station sets a communication channel previously assigned to its own station among the plurality of communication channels to a predetermined period. And communication control means for acquiring and holding the synchronization by receiving the synchronization.
This makes it possible to ensure synchronization accuracy without receiving a control channel.

Fifth, in the fourth mobile communication system, the predetermined cycle is determined by downlink broadcast information transmitted by the base station. This makes it possible to ensure synchronization accuracy without receiving a control channel.

Sixth, in a mobile communication system including a base station and a plurality of mobile stations, the base station constantly transmits a control channel at a fixed frequency and constantly transmits a plurality of communication channels at the same or another frequency. In doing so, transmission is performed by changing the burst length of each of the control channel and the communication channel according to the presence or absence of a call, and the mobile station receives the control channel at a predetermined cycle and is designated by the control channel. A communication control means for knowing the assigned communication channel of the own station is provided. This makes it possible to periodically hold the communication channel information of the base station while reducing battery consumption due to intermittent reception of the control channel.

Seventh, in the sixth mobile communication system, the base station periodically transmits information of a communication channel to be allocated to each mobile station through a control channel that is constantly transmitted, and each of the mobile stations performs control of the control channel. Channels are received at intervals determined by downlink broadcast information transmitted by the base station, and information on a communication channel assigned to the own station is obtained. This makes it possible to periodically re-hold the communication channel information of the base station while reducing battery consumption due to intermittent reception of the control channel.

Eighth, in a mobile communication system including a base station and a plurality of mobile stations, the base station constantly transmits a control channel at a fixed frequency and constantly transmits a plurality of communication channels at the same or another frequency. In doing so, transmission is performed by changing the burst length of each of the control channel and the communication channel according to the presence or absence of a call, and the mobile station is configured to transmit the burst length of the communication channel previously allocated to its own station among the plurality of communication channels. In the standby state to determine the presence or absence of a carrier, enters the reception state when it is determined that the telephone "presence" due to the presence or absence of the carrier, the mobile station is assigned to another mobile station in addition to the communication channel previously assigned to its own station The base station, when communicating by stealing, which is in a state of temporarily using the used communication channel, adjusts the burst length of the control channel. Ete transmitted, the other mobile station comprising the communication control means comprising a standby state by the control channel in place of the communication channel allocated to the own station. As a result, it is possible to reduce the consumption of the battery at the time of communication using the steel.

Ninth, in the eighth mobile communication system, the base station, after terminating the use of the stolen communication channel by the stealing mobile station, only for a period in which the burst length of the control channel is arbitrarily set. Change and send,
If there is no other mobile station in the steal, the transmission continues with the same burst length.If there is a mobile station in the steal, the control channel is transmitted with the original burst length, and the mobile station is in a standby state on the control channel. Is characterized in that the stealed mobile station detects that the stealing has ended by detecting a change in the burst length of the control channel. As a result, the end of the temporary use by the steal and the start of a new call can be determined by the presence or absence of the carrier.

Tenthly, in the ninth mobile communication system, the stolen mobile station detects a change in the burst length of the control channel at intervals determined by presetting. Thereby, the consumption of the battery can be reduced.

Eleventh, in the ninth mobile communication system, the stolen mobile station detects a change in the burst length of the control channel at intervals determined by downlink broadcast information transmitted by the base station. It is characterized by the following. Thereby, the consumption of the battery can be reduced.

Twelfth, in the ninth to eleventh mobile communication systems, after the stealed mobile station detects the end of stealing, the communication channel allocated to the own station is set at intervals determined by presetting. Characterized by entering a standby state. Thereby, the consumption of the battery can be reduced.

Thirteenth, in the ninth to eleventh mobile communication systems, after the stealed mobile station detects the end of the stealing, the mobile station automatically stops at an interval determined by the downlink broadcast information transmitted by the base station. It is characterized by entering a standby state on the communication channel assigned to the station. Thereby, the consumption of the battery can be reduced.

Fourteenth, a communication method for a mobile communication system including a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and simultaneously transmits a plurality of control channels at the same or another frequency. In transmitting the communication channel at all times, the control channel and the communication channel are transmitted with different burst lengths depending on the presence or absence of the communication, and the mobile station is assigned to the mobile station in advance among the plurality of communication channels. It is characterized in that a call "present" is detected from the burst length of the call channel, and a reception state is established. This makes it possible to detect the presence of a call only by determining the presence or absence of a carrier without receiving a call channel, thereby reducing battery consumption.

Fifteenth, a communication method for a mobile communication system including a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and simultaneously transmits a plurality of control channels at the same or another frequency. In transmitting the communication channel at all times, the control channel and the communication channel are transmitted with different burst lengths depending on the presence or absence of the communication, and the mobile station is assigned to the mobile station in advance among the plurality of communication channels. The present invention is characterized in that the burst length of the communication channel is determined at a predetermined cycle to confirm the location. This makes it possible to determine the presence of a base station without receiving a control channel signal.

Sixteenth, in the fifteenth communication method, the predetermined period is determined by downlink broadcast information transmitted by the base station. As a result, it is possible to determine the location of the base station without receiving a control channel signal.

Seventeenth, there is provided a communication method for a mobile communication system including a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and simultaneously transmits a plurality of control channels at the same or another frequency. In transmitting the communication channel at all times, the control channel and the communication channel are transmitted with different burst lengths depending on the presence or absence of the communication, and the mobile station is assigned to the mobile station in advance among the plurality of communication channels. It is characterized in that a communication channel is received at a predetermined cycle to acquire and maintain synchronization. This makes it possible to ensure synchronization accuracy without receiving a control channel.

Eighteenth, in the seventeenth communication method, the predetermined period is determined by downlink broadcast information transmitted by the base station. This makes it possible to ensure synchronization accuracy without receiving a control channel.

Nineteenthly, a communication method for a mobile communication system including a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and simultaneously transmits a plurality of control channels at the same or another frequency. In transmitting the communication channel at all times, the burst length of the control channel and the burst length of the communication channel are changed and transmitted according to the presence or absence of the communication, and the mobile station receives the control channel at a predetermined cycle and performs the control. It is characterized by knowing the assigned communication channel of its own station specified by the channel. As a result, the control channel need only be intermittently received instead of constantly received, so that the battery consumption can be reduced and the communication channel information of the base station can be periodically held again.

Twentiethly, in the nineteenth communication method, the base station periodically transmits information on a communication channel to be allocated to each mobile station on a control channel that is constantly transmitted, and each of the mobile stations uses the control channel. The base station is characterized by receiving information at intervals determined by downlink broadcast information transmitted by the base station and acquiring information of a communication channel allocated to the own station. This makes it possible to periodically hold the communication channel information of the base station while reducing battery consumption due to intermittent reception of the control channel.

Twenty-first, a base station apparatus of a mobile communication system including a base station and a plurality of mobile stations, wherein a control channel is constantly transmitted at a fixed frequency and a plurality of communication channels are transmitted at the same or another frequency. When performing communication by constantly transmitting, communication control means is provided for changing the burst length of each of the control channel and the communication channel in accordance with the presence or absence of a communication and transmitting. As a result, the mobile station can detect the presence of a call only by determining the presence or absence of a carrier based on the length of the burst length without receiving a call channel, thereby reducing battery consumption.

Twenty-second, a base station apparatus of a mobile communication system including a base station and a plurality of mobile stations, which constantly transmits a control channel at a fixed frequency and simultaneously transmits a plurality of communication channels at the same or another frequency. When performing communication by constantly transmitting, the burst length of each of the control channel and the communication channel is changed according to the presence or absence of a call, and transmission is performed. When communicating by stealing in which the communication channel assigned to the station is temporarily used, communication control means for changing the burst length of the control channel for transmission is provided. This allows another stolen mobile station to stand by in the standby state on the control channel, thereby reducing battery consumption during steal communication.

Twenty-third, in the twenty-second base station apparatus, when the communication control means terminates the use of the stolen communication channel by the stealing mobile station, the communication control means only controls the burst length of the control channel for an arbitrarily set period. If the mobile station in the steal does not exist elsewhere, the transmission continues with the same burst length.If the mobile station in the steal exists, the control channel is transmitted with the original burst length. Features. As a result, the end of the temporary use by the steal and the start of a new call can be determined by the presence or absence of the carrier.

Twenty-fourth, a mobile station apparatus of a mobile communication system including a base station and a plurality of mobile stations, which receives a control channel at a fixed frequency and includes a plurality of communication channels at the same or another frequency. When performing communication by receiving a communication channel assigned to the own station, communication control means for detecting a call “present” from a burst length of the communication channel assigned to the own station and entering a reception state is provided. Features. This makes it possible to detect the presence of a call only by determining the presence or absence of a carrier without receiving a call channel, thereby reducing battery consumption.

Twenty-fifth, a mobile station apparatus of a mobile communication system including a base station and a plurality of mobile stations, which receives a control channel at a fixed frequency and receives a plurality of communication channels at the same or another frequency. When performing communication by receiving a communication channel assigned to the own station, communication control means for judging a burst length of the communication channel assigned to the own station at a predetermined cycle and confirming the presence of the communication channel is provided. And As a result, it is possible to determine the location of the base station without receiving a control channel signal.

Twenty-sixth, a mobile station apparatus of a mobile communication system comprising a base station and a plurality of mobile stations, which receives a control channel at a fixed frequency and includes a plurality of communication channels at the same or another frequency. When communication is performed by receiving a communication channel assigned to the own station, communication control means for receiving the communication channel assigned to the own station at a predetermined cycle to acquire and maintain synchronization is provided. And This makes it possible to ensure synchronization accuracy without receiving a control channel.

Twenty-seventh, a mobile station apparatus of a mobile communication system including a base station and a plurality of mobile stations, which receives a control channel at a fixed frequency and includes a plurality of communication channels at the same or another frequency. When performing communication by receiving a communication channel assigned to the own station, communication control means for receiving the control channel at a predetermined cycle and knowing the assigned communication channel of the own station specified by the control channel is provided. It is characterized by having. As a result, it is possible to periodically hold the communication channel information of the base station while reducing battery consumption due to intermittent reception of the control channel.

[0034] Twenty-eighth, a mobile station apparatus of a mobile communication system comprising a base station and a plurality of mobile stations, which receives a control channel at a fixed frequency and includes a plurality of communication channels at the same or another frequency. When performing communication by receiving the communication channel assigned to the own station, the steal, which is in a state of temporarily using the communication channel assigned to another mobile station in addition to the communication channel assigned to the own station in advance. When communicating, the other mobile station that has temporarily used the allocated communication channel has communication control means that is in a standby state by the control channel instead of the communication channel allocated to the mobile station. Features. As a result, it is possible to reduce the consumption of the battery at the time of communication using the steel.

[0035]

Embodiments of the present invention will be described below with reference to the drawings. The embodiment described below uses TDMA
(Time Division Multiple Access) system will be described as an example, but the same concept is applied to FDMA (Frequency
Division Multiple Access).

FIG. 1 is a block diagram of a mobile communication system to which the embodiment of the present invention is applied. In this mobile communication system, a base station 1 and a plurality of mobile stations 2, 3,
Transmission and reception are performed between the transmission lines 4 and 5 using the downlink 6 and the uplink 7. FIG. 2 is a diagram illustrating a frame configuration of a downlink. One frame includes slots 1 to 4, and a control channel or a communication channel is fixedly allocated to each slot. In the example of FIG. 2, the base station transmits a control channel in slot 1 and
In step 4, the communication channels 1 to 3 are transmitted.

In this mobile communication system, the base station 1
Each channel is constantly transmitted. Then, in the normal state, the control channel is transmitted with a regular burst length,
The traffic channel is transmitted with a burst length shorter than the normal burst length. In the example of FIG. 2, a burst of one slot length (normal burst length) is transmitted as a control channel, and a burst of 1/2 slot length (short burst length) is transmitted as a traffic channel. The mobile station performs transmission / reception using any of the communication channels 1 to 3 assigned in advance.

FIG. 3 is a block diagram showing a schematic configuration of a communication device used in a mobile communication system. Here, only a schematic configuration of a main part of a communication device used for the base station or the mobile station is shown, and a difference between the configuration of the base station and the mobile station is omitted. Generally, a base station has a plurality of wireless communication units.

The communication device 30 includes an antenna 31 for transmitting and receiving a radio signal, an antenna duplexer 32 for switching between a transmission system and a reception system, a receiving unit 33 for demodulating a received signal, and a transmission for modulating and amplifying a transmitted signal. A signal processing unit 35 for performing various kinds of signal processing of the baseband signal, such as encoding of a transmission signal and decoding of a reception signal, and a control unit 36 for controlling operation of each unit. The control unit 36 includes a communication control unit that performs various controls related to transmission and reception operations.

FIG. 4 is a timing chart of transmission and reception in the mobile communication system according to the first embodiment of the present invention. It is assumed that the communication channel 2 is assigned to the mobile station. In the first embodiment, the base station transmits a burst having a half slot length to each of the communication channels 1 to 3 on the downlink in a non-communication state. The mobile station establishes a period T
In step 1, the presence / absence of a carrier is determined at an arbitrary position after the 1/2 slot length, and if a carrier cannot be detected, a standby operation is started.

FIG. 5 is a timing chart when a call is started. When a call starts, the base station changes the burst length of the call channel 2 to a normal burst length and transmits a call signal. The mobile station, in the control unit 36, the period T1
, The presence or absence of a carrier is determined. When a burst is detected on the communication channel 2, it is determined that there is a carrier, and the start of a call can be detected. This allows the mobile station to:
The receiving unit 33 and the signal processing unit 35 are activated, and the reception of the communication channel 2 and the decoding of the received signal such as voice are started from the next frame. Here, the above-mentioned cycle T1 is determined by presetting stored in advance, notification from the base station by broadcast information, and the like. In the illustrated example, the cycle T1 is the same as the cycle of one frame.

According to this embodiment, the base station changes the burst length of the communication channel between a call and a non-communication and transmits the signal, so that the mobile station starts the call only by determining the presence or absence of the carrier of the communication channel. Can be detected. For this reason, it is not necessary to activate a signal processing unit or the like that consumes a large amount of power even when there is no call, and it is possible to reduce battery consumption of the mobile station.

FIG. 6 is a timing chart of transmission and reception according to the second embodiment of the present invention. In the second embodiment, the base station transmits a 1/2 slot length burst to each of the communication channels 1 to 3 on the downlink. Under the control of the control unit 36, the mobile station sets a period T2 twice as long as one frame for the pre-assigned speech channel 2.
Then, an arbitrary range of 1/2 slot during the burst transmission is received, and the presence or absence of the carrier is determined. If a carrier can be detected, the mobile station determines that the mobile station is located and enters a standby operation. If no carrier is detected, it determines that the mobile station is out of service. If it is out of the service area, the operation of the signal processing unit 35 and the like is stopped. The cycle T2 is determined by presetting and storing in advance, notification by broadcast information, or the like. However, the cycle T2 does not need to be the two-frame cycle as described above, and may be a longer cycle.

According to this embodiment, the base station constantly transmits the communication channel, so that the mobile station can determine whether the mobile station is in or out of service by determining the presence or absence of the carrier. Therefore, there is no need to activate a signal processing unit or the like that consumes a large amount of power, and it is possible to reduce battery consumption of the mobile station.

FIG. 7 is a timing chart of transmission and reception according to the third embodiment of the present invention. In the third embodiment, the base station constantly transmits a 1/2 slot length burst to each of the communication channels 1 to 3 on the downlink. Under the control of the control unit 36, the mobile station performs intermittent reception at a cycle T3 with respect to the communication channel 2 allocated in advance, and secures synchronization accuracy. The cycle T3 is determined by presetting and storing in advance or notification based on broadcast information. However, the cycle T3 does not need to be a two-frame cycle as shown in the figure, and may be a longer cycle.

In this embodiment, the mobile station performs intermittent reception at period T3 instead of determining the presence or absence of a carrier, and the base station constantly transmits a communication channel, thereby maintaining synchronization with the base station. it can. As a result, unnecessary operation for ensuring synchronization can be eliminated, and power consumption can be suppressed.

FIG. 8 is a flowchart showing the operation of a mobile station having the first, second, and third embodiments described above. First, it is determined whether the period T1 has elapsed (step S1). If the period T1 has elapsed (Yes), the process proceeds from step S1 to step S2, where the latter half of the slot of the corresponding traffic channel is checked to perform carrier detection, and the process proceeds to the next step S3. In step S3, the presence or absence of a carrier in the latter half of the slot is determined. If the carrier is "present", the flow advances to step S9 to start receiving the communication channel, receive the next frame and thereafter, and end the communication (step S10). After that step S
Return to 1.

The result of the determination in step S3 is that the carrier is "absent"
If so, the process proceeds to step S4, where it is determined whether the period T2 has elapsed. In step S1, the period T1
This step S is also performed when it is determined that
Proceed to 4. The determination result in step S4 is positive (Yes)
In other words, if the period T2 has elapsed, step S
Proceed to 5 to detect the carrier in the first half of the slot of the traffic channel, and proceed to the next step S6. In step S6,
It is determined whether or not the carrier is present. If the carrier is "absent", the process proceeds to step S11, where it is determined that the mobile station is currently "out of range", and the process returns to step S1. If the determination result in step S4 is negative (No), that is, if the period T2 has not elapsed, the process skips step S5 and proceeds to step S6.

If it is determined in step S6 that the carrier is "present", the flow advances to step S7 to determine whether the period T3 has elapsed. If the time has not elapsed, the process returns to step S1, and if the time has elapsed, the process proceeds to the next step S8, where a communication channel is received to acquire and hold synchronization, and the process returns to step S1.

As described above, the presence / absence of a call is determined for each frame, and whether the area is out of service or in service is determined for every several frames. Similarly, synchronization is obtained by intermittently receiving every several frames. The power consumption can be reduced by reducing the number of times of activation of the signal processing unit and the like, and the life of the battery can be extended.

FIG. 9 is a timing chart of transmission / reception according to the fourth embodiment of the present invention. In the fourth embodiment, the base station transmits control channel 1 that is always transmitted on the downlink.
To transmit not only the information of the own station but also the communication channel information such as the frequency of the communication channel assigned to the own station and the slot position. The mobile station, under the control of the control unit 36,
The control channel 1 is intermittently received at a period T4, and the communication channel information in the mobile station is updated. That is, the mobile station that has received the communication channel information compares the previously held communication channel information with the received communication channel information, and if the information is different, changes the frequency according to the latest information. The cycle T4 at which the communication channel information is updated is determined by a preset preset or stored notification or notification by broadcast information.

According to this embodiment, the base station transmits the information of the communication channel allocated to the base station on the control channel, so that the mobile station periodically and intermittently receives the control channel, thereby updating the mobile station to the latest. Based on the traffic channel information thus obtained, it is possible to detect a change in the traffic channel and an inflow to another base station zone, and to continue standby and reception on the allocated traffic channel. As a result, it is possible to prevent a problem that a call cannot be made, and it is possible to eliminate unnecessary operation during reception and suppress power consumption.

FIG. 10 is a timing chart of transmission / reception according to the fifth embodiment of the present invention. In this example, the communication channel 1 is assigned to the mobile station a in advance, and the communication channel 2 is assigned to the mobile station b in advance. In the fifth embodiment, when there is no communication, the base station always transmits control channel 1 with a one-slot length on the downlink and constantly transmits each of communication channels 1 to 3 with a half-slot length. (B-1). Here, the communication channel allocated to another mobile station is temporarily used (hereinafter, “steal”).
) Will be described.

After the mobile station a starts talking on the communication channel 1 (a-1), the communication channel 2 assigned to the mobile station b is started.
Then, when the communication is started (a-2), the base station changes the burst of the control channel 1 to a half slot length and transmits it (b-2). The mobile station b performing the determination (c-1) of the presence or absence of the carrier of the communication channel 2 in the cycle T1 detects the carrier "present" after the above stealing (c-
2). Therefore, the mobile station b receives the traffic channel 2 of the next frame (c-3). The mobile station b analyzes the received signal, detects that the channel 2 is stolen from the received content, shifts to the control channel 1 in the next frame, and enters a standby state (c-
4).

The reason why the mobile station b shifts to the control channel 1 is as follows. That is, when the mobile station b does not shift to the control channel 1 and continues the normal standby operation on the communication channel 2, the mobile station b performs carrier detection, reception, and reception until the mobile station a steals the communication channel 2. This is because the signal analysis is repeated every two frames in the example of FIG. 10, and the battery is consumed by unnecessary power consumption.

According to this embodiment, when a mobile station performs a call by channel stealing, the base station changes the burst length of the control channel and transmits the signal, whereby the stealed mobile station shifts to the control channel. As a result, the mobile station can enter a standby state, thereby reducing battery consumption of the mobile station.

FIG. 11 is a timing chart of transmission / reception according to the sixth embodiment of the present invention, which is an operation continued from FIG. 10 of the fifth embodiment. The base station transmits the control channel 1 with a 1/2 slot length, the communication channels 1 and 2 during communication each with a 1 slot length, and the communication channel 3 during non-communication with a 1/2 slot length. (B
-1). The mobile station a in the channel stealing is communicating using the communication channel 1 and the communication channel 2 (a-
1) As a result, the mobile station b in the standby state on the control channel 1 as described with reference to FIG. 10 determines the presence or absence of a carrier of the control channel 1 in the cycle T1 (c-1).

When the mobile station a terminates the use of the speech channel 2 by stealing (a-2), the base station forcibly transmits the control channel 1 with one slot length only during the period T5 (b-2). ). Then, after the elapse of the period T5, the base station transmits the control channel 1 with the same burst length if no other mobile station is stealing, and if the stealing mobile station exists, the base station transmits the control channel 1. 1 to 1/2
Make the slot length. When the mobile station b detects a carrier in the determination of the presence or absence of the carrier in the cycle T1 in the control channel 1 (c-2), the presence or absence of the carrier at an arbitrary position (the latter half of the slot) behind the half slot length of the speech channel 2 Is determined (c-3).

If no carrier is detected, it is determined that the stealing by the mobile station a has been completed, and the mobile station a enters a standby state on the same channel 2. When the carrier is detected, the communication channel 2 of the next frame is received and the signal is analyzed as described with reference to FIG. 10, and if the received content is the communication of the channel, the communication state is immediately entered. In cases other than the above, the control shifts to the control channel 1 again in the next frame to enter the standby state. This period T5 is also determined by presetting which is set and stored in advance.

According to this embodiment, when the mobile station in channel stealing has finished using the slot, it transmits by changing the burst length of the control channel for an arbitrarily set period, so that the mobile station stands by on the control channel. The mobile station in the state can return to the communication channel in a short time. As a result, the problem of the beginning of the talk occurring in the press talk communication or the like having no call connection procedure can be avoided.

FIG. 12 is an SDL (Specification and Description Language) chart showing the operation of the base station when the mobile station in channel stealing has finished using the channel. This SDL chart includes a chart “0” (shown in FIG. 12A) in an “idle” state and a chart “1” (shown in FIG. 12 (B)) in a state of “mobile station using another station channel”. And a chart "2" (shown in FIG. 12C) in a "control channel burst length changing" state.

When the chart enters the idle state “0”,
After performing the temporary use start process 01 of the channel allocated to the other station and the process 02 of transmitting data with a half slot length of the control channel, the process proceeds to the chart “1”.

When the chart "1" is entered, the process is temporarily divided into a process 11 for temporarily using the channel allocated to another station and a process 14 for starting the temporary use of the channel allocated to another station. Return to Subsequent to the processing 11, a processing 12 for transmitting the control channel 1 with a length of one slot is performed.
The process 13 for starting the timer to start counting the period T5 is performed, and the process proceeds to chart "2".

When entering the chart "2", the timer is set to the period T.
5, a process 24 for waiting for the time-out of the channel 5, a process 24 for releasing the temporary use of the channel allocated to another station, and a process for starting the temporary use of the channel allocated to another station. The process proceeds to a process 22 for determining whether or not the channel is in use. In the case of “absent”, the process returns to the chart “0”. In the case of “available”, the process of transmitting the next control channel with a １ ／ slot length After performing step 23, the flow shifts to chart "1". After the process 24, that is, after the stealing is completed, the timer is started to perform a process 25 for starting the counting of the period T5, and the process returns to the beginning of the chart "2". After the process 26, that is, after the start of the stealing, the process returns to the beginning of the chart "2".

In the above-described embodiment, the burst length of the communication channel in which no communication is performed is set to 1/2 slot length, and the burst length of the control channel in the channel steal is changed to 1/2 slot length. Although described, if each burst length is different from the normal burst length, the present invention is not limited to １ ／ and can be similarly implemented. Also, the case where slot 2 is allocated as a communication channel for steal has been illustrated, but the present invention can be similarly implemented by allocating another slot.

In the above description, the case where the control channel and the communication channel have the same frequency has been described as an example. However, the present invention can be similarly applied to other frequencies. Also, the case where the number of multiplexed TDMA channels is 4 has been illustrated,
Other multiplex numbers can be similarly implemented. Further, as described above, the present invention is applied to another FDMA (Frequency Divi
The same is applicable to the case of the sion multiple access method.

[0067]

As described above, according to the present invention, in a mobile communication system including a base station and a plurality of mobile stations, the base station constantly transmits a control channel at a fixed frequency and simultaneously transmits the same or another frequency. In transmitting multiple communication channels at all times, the burst length of each signal is changed according to the presence or absence of a call, and the mobile station detects the difference in the burst length in the slot allocated to its own station and talks. By determining the presence / absence and entering the reception state when there is a call, the consumption of the battery can be reduced, and the time required to stop talking can be reduced.

The mobile station can confirm the location by determining at predetermined intervals the presence or absence of the carrier of the communication channel constantly transmitted from the base station in the slot assigned to the mobile station in advance. By receiving a communication channel constantly transmitted from the base station at an arbitrary interval in a slot allocated to the station, synchronization can be obtained and maintained.

[Brief description of the drawings]

FIG. 1 is a block diagram of a mobile communication system according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a downlink frame configuration of the mobile communication system illustrated in FIG. 1;

FIG. 3 is a block diagram illustrating a schematic configuration of a communication device used for a mobile communication system.

FIG. 4 is a timing chart of transmission and reception according to the first embodiment of the present invention.

FIG. 5 is a timing chart at the start of a call according to the first embodiment of the present invention.

FIG. 6 is a timing chart of transmission and reception according to a second embodiment of the present invention.

FIG. 7 is a timing chart of transmission and reception according to a third embodiment of the present invention.

FIG. 8 is a flowchart showing an operation procedure of a mobile station having both the first to third embodiments of the present invention.

FIG. 9 is a timing chart of transmission and reception according to a fourth embodiment of the present invention.

FIG. 10 is a timing chart of transmission and reception according to a fifth embodiment of the present invention.

FIG. 11 is a timing chart of transmission and reception according to a sixth embodiment of the present invention.

FIG. 12 is an SDL chart showing an operation of the base station according to the sixth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 base station 2, 3, 4, 5 mobile station 6 downlink 7 uplink 30 communication device (base station / mobile station) 33 reception unit 34 transmission unit 35 signal processing unit 36 control unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K027 AA11 BB03 BB04 BB17 CC08 EE11 FF02 FF22 GG03 GG08 KK03 5K067 AA43 DD11 EE02 EE10 EE71 EE72 FF16 JJ12

Claims (28)

[Claims] 1. A mobile communication system comprising a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and constantly transmits a plurality of communication channels at the same or another frequency. The mobile station changes the burst length of each of the control channel and the communication channel according to the presence or absence of a call, and transmits. The mobile station performs communication based on the burst length of the communication channel assigned to itself in advance among the plurality of communication channels. A mobile communication system comprising communication control means for detecting presence and in a receiving state. 2. A mobile communication system comprising a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and constantly transmits a plurality of communication channels at the same or another frequency. The mobile station changes the burst length of each of the control channel and the traffic channel according to the presence or absence of a call and transmits the data. The mobile station determines a burst length of a traffic channel previously allocated to the mobile station among the plurality of traffic channels. A mobile communication system comprising: a communication control unit that determines a period and confirms a location. 3. The mobile communication system according to claim 2, wherein the predetermined cycle is determined by downlink broadcast information transmitted by the base station. 4. A mobile communication system comprising a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and constantly transmits a plurality of communication channels at the same or another frequency. Transmitting the control channel and the communication channel with different burst lengths according to the presence or absence of a communication, and the mobile station receives a communication channel previously allocated to the own station at a predetermined cycle among the plurality of communication channels. And a communication control means for acquiring and maintaining synchronization. 5. The mobile communication system according to claim 4, wherein said predetermined period is determined by downlink broadcast information transmitted by said base station. 6. A mobile communication system comprising a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and simultaneously transmits a plurality of communication channels at the same or another frequency. The mobile station receives the control channel at a predetermined cycle while changing the burst length of each of the control channel and the traffic channel in accordance with the presence or absence of a call, and transmits the mobile station specified by the control channel. A mobile communication system comprising communication control means for knowing the allocated call channel. 7. The mobile station according to claim 6, wherein the base station periodically transmits information on a communication channel to be allocated to each mobile station on a control channel that is constantly transmitted, and each mobile station transmits the control channel by the base station. A mobile communication system characterized by receiving information of a communication channel received at intervals determined by downlink notification information to be allocated to the mobile station. 8. A mobile communication system comprising a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and constantly transmits a plurality of communication channels at the same or another frequency. The mobile station changes the burst length of each of the control channel and the traffic channel according to the presence or absence of a call, and transmits the signal. It becomes a standby state to determine the presence / absence, and enters a reception state when it is determined that a call is "present" based on the presence or absence of a carrier,
When the mobile station communicates by stealing, in which the mobile station temporarily uses the communication channel allocated to another mobile station in addition to the communication channel allocated to the mobile station in advance, the base station determines the burst length of the control channel. Change and send,
The mobile communication system according to claim 1, wherein the other mobile station includes a communication control unit that enters a standby state by the control channel instead of the communication channel assigned to the mobile station. 9. The base station according to claim 8, wherein, when the stealing mobile station ends using the stolen communication channel, the base station changes the burst length of the control channel for an arbitrarily set period and transmits the control channel. If there is no other mobile station, the transmission continues with the same burst length, and if there is a stealing mobile station, the control channel is transmitted with the original burst length, and the mobile station that is on standby on the control channel is transmitted. A mobile communication system, wherein a steal mobile station detects the end of the steal by detecting a change in a burst length of the control channel. 10. The mobile station according to claim 9, wherein the stealed mobile station determines a change in the burst length of the control channel.
A mobile communication system wherein detection is performed at intervals determined by presetting. 11. The stolen mobile station according to claim 9, wherein the stolen mobile station changes the burst length of the control channel.
A mobile communication system wherein detection is performed at intervals determined by downlink broadcast information transmitted by a base station. 12. The communication channel according to claim 9, wherein after the stealed mobile station detects the end of stealing, the mobile station uses the communication channel allocated to the own station at intervals determined by presetting. A mobile communication system characterized by entering a standby state. 13. The mobile station according to claim 9, wherein after the stealed mobile station detects the end of the stealing, the mobile station sends the stealed mobile station at intervals determined by downlink broadcast information transmitted by the base station. A mobile communication system, wherein the mobile communication system enters a standby state on an allocated communication channel. 14. A communication method for a mobile communication system comprising a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and a plurality of communication channels at the same or another frequency. In transmitting constantly, the mobile station changes the burst length of each of the control channel and the communication channel according to the presence or absence of a communication, and transmits the mobile station. A communication method characterized in that a call "Yes" is detected from a burst length of the communication and a reception state is set. 15. A communication method for a mobile communication system comprising a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and a plurality of communication channels at the same or another frequency. In transmitting constantly, the mobile station changes the burst length of each of the control channel and the communication channel according to the presence or absence of a communication, and transmits the mobile station. A communication method characterized in that the burst length of the communication is determined at a predetermined cycle to confirm the location. 16. The communication method according to claim 15, wherein said predetermined period is determined by downlink broadcast information transmitted by said base station. 17. A communication method for a mobile communication system comprising a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and a plurality of communication channels at the same or another frequency. In transmitting constantly, the mobile station changes the burst length of each of the control channel and the communication channel according to the presence or absence of a communication, and transmits the mobile station. Receiving at a predetermined period, and acquiring and holding synchronization. 18. The communication method according to claim 17, wherein the predetermined period is determined by downlink broadcast information transmitted by the base station. 19. A communication method for a mobile communication system comprising a base station and a plurality of mobile stations, wherein the base station constantly transmits a control channel at a fixed frequency and a plurality of communication channels at the same or another frequency. When constantly transmitting, the burst length of each of the control channel and the traffic channel is changed according to the presence or absence of a call and transmitted, and the mobile station receives the control channel at a predetermined cycle and receives the control channel. A communication method characterized by knowing an assigned communication channel of a designated own station. 20. The mobile station according to claim 19, wherein the base station periodically transmits information of a communication channel to be allocated to each mobile station on a control channel that is constantly transmitted, and each mobile station transmits the control channel by the base station. A communication method characterized by acquiring information of a communication channel received at intervals determined by downlink notification information to be allocated to the own station. 21. A base station apparatus for a mobile communication system comprising a base station and a plurality of mobile stations, wherein the base station always transmits a control channel at a fixed frequency and constantly transmits a plurality of communication channels at the same or another frequency. A base station apparatus comprising: a communication control unit configured to perform transmission by changing a burst length of each of the control channel and the communication channel in accordance with the presence or absence of a communication when performing communication. 22. A base station apparatus for a mobile communication system comprising a base station and a plurality of mobile stations, wherein the base station always transmits a control channel at a fixed frequency and constantly transmits a plurality of communication channels at the same or another frequency. When performing communication by changing the burst length of each of the control channel and the communication channel according to the presence or absence of a call, and transmitting, the mobile station to the other mobile station in addition to the communication channel previously assigned to its own station When communicating by steal, which is in a state of temporarily using the assigned call channel,
A base station apparatus comprising communication control means for changing the burst length of the control channel for transmission. 23. The communication control means according to claim 22, wherein, when the stealing mobile station terminates use of the stolen communication channel, the communication control means changes the burst length of the control channel by an arbitrarily set period and transmits. A base station apparatus, wherein when there is no other mobile station in stealing, transmission continues with the same burst length, and when there is a mobile station in stealing, the control channel is transmitted with the original burst length. . 24. A mobile station apparatus of a mobile communication system comprising a base station and a plurality of mobile stations, the mobile station apparatus receiving a control channel at a fixed frequency, and receiving a control channel out of a plurality of communication channels at the same or another frequency. When performing communication by receiving a call channel assigned to the station, the communication control means for detecting a call `` Yes '' from the burst length of the call channel assigned to the own station and entering a reception state, comprising: Mobile station equipment. 25. A mobile station device of a mobile communication system comprising a base station and a plurality of mobile stations, comprising: a control station receiving a control channel at a fixed frequency; When performing communication by receiving a communication channel assigned to a station, the communication control unit includes a communication control unit that determines a burst length of the communication channel assigned to the own station at a predetermined cycle and confirms the location. Mobile station equipment. 26. A mobile station device of a mobile communication system comprising a base station and a plurality of mobile stations, the mobile station device receiving a control channel at a fixed frequency and a local station among a plurality of communication channels at the same or another frequency. When performing communication by receiving a communication channel assigned to a station, the communication apparatus includes communication control means for receiving the communication channel assigned to the own station at a predetermined cycle to acquire and hold synchronization. Mobile station equipment. 27. A mobile station apparatus of a mobile communication system comprising a base station and a plurality of mobile stations, comprising: a control channel receiving a control channel at a fixed frequency; When communication is performed by receiving a communication channel assigned to a station, communication control means for receiving the control channel at a predetermined cycle and knowing the allocated communication channel of the own station designated by the control channel is provided. A mobile station device characterized by the above-mentioned. 28. A mobile station device of a mobile communication system comprising a base station and a plurality of mobile stations, comprising: a mobile station receiving a control channel at a fixed frequency; When communication is performed by receiving a communication channel assigned to a station, communication is performed by stealing, in which the communication channel assigned to another mobile station is temporarily used in addition to the communication channel assigned to the own station in advance. When the other mobile station that has temporarily used the allocated communication channel is provided with communication control means that is in a standby state by the control channel instead of the communication channel allocated to the mobile station. Mobile station equipment.