JP2001346241A - Digital mobile communication system and digital mobile communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that any access system should have been selected in the case of building up a new digital mobile communication system. SOLUTION: In a service area where a TDMA base station 2 that transmits/ receives digital data by the TDMA system and an FDMA base station 3 that transmits/receives digital data by the FDMA system are intermingled, a mobile station 4 sends/receives digital data by the TDMA system with the TDMA base station 2 in a zone 5 covered by the TDMA base station 2 and sends/ receives digital data by the FDMA system with the FDMA base station 3 in a zone 6 covered by the FDMA base station 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital mobile communication system and a digital mobile communication method for wirelessly transmitting and receiving digital data between a base station and a mobile station.

[0002]

2. Description of the Related Art Digital systems for mobile communication systems are being developed because various services such as frequency utilization efficiency and communication confidentiality can be provided.

In a digital mobile communication system, TDMA (Time Division Multip
le Access) method has been used. In the TDMA system, a wireless carrier is divided into frames at fixed time intervals,
Each frame is divided into a number of slots corresponding to the number of multiplexes. In the TDMA system, a plurality of users use one wireless channel in a time-division manner.
Although suitable for large-capacity transmission, it is necessary to synchronize with each other so that signals in each slot are not superimposed, and an advanced synchronization control technique is required.

[0004] Regarding the standard of such a TDMA mobile communication system, for example, RCRSTD-39A
("Public business digital mobile communication system" standard,
Edited by the Association of Radio Industries and Businesses).

[0005] On the other hand, as another access method for a radio channel of a digital mobile communication system, FDMA (Frequency Di- rectification) is used.
vision Multiple Access) system has also been proposed. TD
In the MA system, multiplexing is performed using a plurality of wireless carriers having frequencies that do not overlap each other. In the FDMA scheme, a wireless carrier is divided into frames at regular intervals, but since one user uses one wireless channel, the frame is not divided into a plurality of slots as in the TDMA scheme. Therefore, TD
It is more suitable for wireless transmission in a narrow zone than the MA system.

[0006]

Since the conventional digital mobile communication system is configured as described above, when constructing a new digital mobile communication system, the advantages and disadvantages of the two access systems of the TDMA system and the FDMA system are obtained. There is a problem that one of the access methods must be selected in consideration of the above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a service area in which a TDMA base station for transmitting and receiving digital data by the TDMA method and an FDMA base station for transmitting and receiving digital data by the FDMA method are mixed. The mobile station transmits and receives digital data to and from the TDMA base station in the TDMA base station zone by the TDMA scheme, and transmits and receives digital data to and from the FDMA base station by the FDMA scheme in the FDMA base station zone. And TDMA system and FDMA system
An object of the present invention is to provide a digital mobile communication system and a digital mobile communication method that can make use of the features of each of two different access methods.

[0008]

A digital mobile communication system according to the present invention includes a TDMA base station for transmitting and receiving digital data according to the TDMA system, an FDMA base station for transmitting and receiving digital data according to the FDMA system, and a zone for the TDMA base station. In the zone of the FDMA base station, a mobile station that transmits and receives digital data to and from the FDMA base station by the FDMA system in the zone of the FDMA base station, and a plurality of TDMA base stations and FDMA base stations. And a control station for establishing a line with the mobile station via any of the stations.

A digital mobile communication system according to the present invention provides a digital data slot and F
In this system, a relative position on a time axis with respect to a frame of digital data by the DMA method is fixed.

In the digital mobile communication system according to the present invention, a relative position on a time axis between a superframe of digital data based on the TDMA system and a superframe of digital data based on the FDMA system is fixed.

[0011] In the digital mobile communication system according to the present invention, the frame length of digital data according to the FDMA system is the same as the frame length of digital data according to the TDMA system.

A digital mobile communication system according to the present invention performs common baseband processing on digital data transmitted by the TDMA method and digital data transmitted by the FDMA method, and executes digital data received by the TDMA method. And a baseband processing unit for commonly performing baseband processing on digital data received by the FDMA system.

[0013] In the digital mobile communication system according to the present invention, the zone of the TDMA base station and the zone of the FDMA base station overlap at least partially.

[0014] In the digital mobile communication system according to the present invention, the control station is configured such that the mobile station has a zone of a TDMA base station and an FD.
When the mobile station is located in an overlapping zone of the MA base station, the TDMA system or the FDMA system is selected according to the traffic.

In the digital mobile communication system according to the present invention, the control station selects the TDMA system when the traffic amount is larger than a predetermined value, and selects the FDMA system when the traffic amount is equal to or smaller than the predetermined value. It was made.

In the digital mobile communication system according to the present invention, an area other than a zone of a TDMA base station among fixed service areas is constituted by a zone of an FDMA base station.

[0017] A digital mobile communication method according to the present invention comprises:
TDMA for transmitting and receiving digital data by TDMA method
In a service area where a base station and an FDMA base station that transmits and receives digital data according to the FDMA scheme are mixed, a mobile station can use a TDMA scheme in a TDMA base station zone.
Sends and receives digital data to and from the DMA base station,
In the zone of the A base station, digital data is transmitted to and received from the FDMA base station by the FDMA method.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram showing a configuration of a digital mobile communication system according to Embodiment 1 of the present invention. FIG. 2 is a block diagram showing a configuration of a mobile station in the digital mobile communication system according to Embodiment 1.
FIG. 3 is a block diagram showing a configuration of a baseband processing unit of the mobile station in FIG.

In FIG. 1, reference numeral 1 denotes a mobile station 4 via one of a plurality of TDMA base stations 2 and FDMA base stations 3.
2 is a TDMA base station for transmitting and receiving digital data to and from the mobile station 4 existing in its own zone 5 by the TDMA system, and 3 is a control station for establishing its own zone 6. An FDMA base station for transmitting / receiving digital data to / from an existing mobile station 4 by the FDMA method. Reference numeral 4 denotes a zone 5 for transmitting / receiving digital data to / from the TDMA base station 2 by the TDMA method.
The mobile station transmits and receives digital data to and from the FDMA base station 3 according to the DMA method. 7 is for zones 5 and 6
Are overlapping zones.

In the mobile station 4 shown in FIG. 2, reference numeral 11 denotes a voice codec unit which converts voice signals into voice data and converts voice data into voice signals. Reference numeral 12 denotes a microcomputer that executes various processes and sends and receives various control data.

Reference numeral 13-1 executes baseband processing such as channel coding, coding, encryption, and scrambling on voice data and control data transmitted by the TDMA method, and converts the received data into the TDMA method. On the other hand, a baseband processing unit that performs baseband processing such as decryption, decryption processing, descrambling processing, and channel decoding.
Performs baseband processing such as channel coding, coding, encryption, and scrambling on voice data and control data transmitted in the A-method, and decrypts and encrypts data and the like received in the FDMA method. A baseband processing unit that performs baseband processing such as decoding processing, descrambling processing, and channel decoding.

The baseband processing unit 13-1 shown in FIG.
In 13-2, reference numeral 41 denotes an audio data coding unit for synthesizing audio data and control data into one data of a predetermined format, and reference numeral 42 adds various information necessary for wireless communication to data from the audio data coding unit 41. A channel coding unit 43 for constructing data of one slot or one frame, an encryption unit 43 for encrypting data to be transmitted by a predetermined encryption method, and a scrambling process 44 for the data to be transmitted. Reference numeral 45 denotes an encoding unit that executes encoding processing such as CRC (Cyclic Redundancy Code) encoding for error correction, convolutional encoding, and interleaving.

Reference numeral 51 denotes a decoding unit for executing a decoding process of a method corresponding to the encoding unit 45 on the received data, and 52 a descrambling process for executing the descrambling process on the received data. 53, a decryption unit for decrypting the received encrypted data, 54, a channel decoding unit for extracting a data portion (voice data and control data) of the received data, Reference numeral 55 denotes an audio data extraction unit that classifies the data portion extracted by the channel decoding unit 54 into audio data and control data.

Reference numeral 14 denotes a transmitting unit 21 for transmitting data from the baseband processing unit 13-1 in the TDMA system,
A receiving unit 22 that receives data transmitted by the TDMA method from the base station 2, and a transmitting unit 21 and a receiving unit 22
Having a synthesizer 23 for supplying a local oscillation signal to the
This is a DMA radio unit. 15 is a baseband processing unit 13-
A transmitting unit 31 for transmitting the data from F.2 in the FDMA scheme;
The FDMA radio unit includes a receiving unit 32 that receives data transmitted by the FDMA system from the FDMA base station 3 and a synthesizer 33 that supplies a local oscillation signal to the transmitting unit 31 and the receiving unit 32. Reference numeral 16 denotes an antenna unit that emits radio waves and senses them.

Next, the operation will be described. The mobile station 4
Based on an access mode selection signal transmitted from the TDMA base station 2 or FDMA base station 3 in the zone 5 or 6 where the mobile station is located, the access mode is set to TDMA mode or FDM mode.
Select the A method. Therefore, the mobile station 4
When the mobile station exists in the zone 5 of the base station 2, the TDMA system is selected as the access system, and the wireless communication with the TDMA base station 2 is executed. Further, when the mobile station 4 exists in the zone 6 of the FDMA base station 3, the mobile station 4 selects the FDMA scheme as an access scheme and performs wireless communication with the FDMA base station 3.

When the TDMA system is selected, in the mobile station 4, as a transmission process, the audio signal is converted into audio data by the audio codec section 11, and the audio data is transmitted to the base station together with the control data from the microcomputer 12. After being subjected to various kinds of baseband processing by the band processing unit 13-1, the signal is supplied to the TDMA radio unit 14. The TDMA radio unit 14 converts the supplied data into a TDM
The signal is transmitted via the antenna unit 16 in the A method. On the other hand, as a receiving process, the TDMA radio unit 1
The data received by the baseband processing unit 13-
1 is supplied. The baseband processing unit 13-1 performs various baseband processes on the data to convert the data into original audio data and control data, and then supplies the audio data to the audio codec 11, and transmits the control data to the microcomputer 12 To supply.

When the FDMA system is selected, the mobile station 4 converts a voice signal into voice data by the voice codec unit 11 as transmission processing, and the voice data is transmitted together with control data from the microcomputer 12. After being subjected to various baseband processes by the baseband processor 13-2, the baseband is supplied to the FDMA radio unit 15. The FDMA radio unit 15 converts the supplied data into F
Data is transmitted via the antenna unit 16 in the DMA system. on the other hand,
As a reception process, data received by the FDMA radio unit 15 via the antenna unit 16 is transmitted to the baseband processing unit 1
3-2. The baseband processing unit 13-2
After performing various baseband processes on the data and converting the data into original voice data and control data, the voice data is supplied to the voice codec 11 and the control data is supplied to the microcomputer 12.

Then, the control station 1 establishes a line with the mobile station 4 via the TDMA base station 2 or the FDMA base station 3.

Further, the zone 5 of the TDMA radio station 2 and the FD
When the mobile station 4 exists in the overlapping zone 7 where the zone 6 of the MA radio station 3 overlaps, the mobile station 4 depends on the status of the radio propagation environment and the status of the traffic in the overlapping zone 7 (hereinafter referred to as “system status”). Then, the mobile station 4 selects an optimal access method from the two access methods, and executes the wireless communication in the selected method as described above.

At this time, the control station 1 monitors the status in the system, and accordingly, T
Select the DMA base station 2 or the FDMA base station 3. The selected base station transmits an access method selection signal to the mobile station 4, and the mobile station 4 selects an access method based on the access method selection signal. The operation inside the mobile station 4 is as described above.

As described above, according to the first embodiment, the TD for transmitting and receiving digital data by the TDMA method is used.
In a service area in which the MA base station 2 and the FDMA base station 3 that transmits and receives digital data according to the FDMA scheme are mixed, the mobile station 4 performs TD in the zone 5 of the TDMA base station 2.
Digital data is transmitted to and received from the MA base station 2 by the TDMA method.
Since digital data is transmitted / received to / from the base station 3 by the FDMA method, a digital mobile communication system can be constructed by utilizing the features of two different access methods, the TDMA method and the FDMA method. The effect is obtained.

Embodiment 2 FIG. In the digital mobile communication system according to the second embodiment of the present invention, a relative position on a time axis between a digital data slot according to the TDMA scheme and a frame of digital data according to the FDMA scheme is fixed. In the digital mobile communication system according to Embodiment 2 of the present invention, the frame length of digital data according to the FDMA system is the same as the frame length of digital data according to the TDMA system.

FIG. 4 is a diagram showing an example of the correspondence between the slot configuration of the TDMA system and the frame configuration of the FDMA system used in the digital mobile communication system according to the second embodiment of the present invention. As shown in FIG.
In the slot configuration in the A method, a plurality of slots (in this case,
One frame is composed of four (4) slots.
Note that the number of slots in one frame is not limited to four. On the other hand, in the frame configuration in the FDMA system, T
There is no concept like a slot in the DMA system.

In the digital mobile communication system according to the second embodiment, as shown in FIG. 4, the slot start position (or frame start position) and the FD in the TDMA system are used.
The relative deviation from the frame start position in the MA system (time difference Δ in the figure, including the case where time difference Δ = 0) is fixed. Further, the length of one frame of the TDMA system is the same as the length of one frame of the FDMA system.

In the digital mobile communication, regardless of the access method, the digital data to be transmitted is as shown in FIG.
And is transmitted in units of slots or frames. Then, on the receiving side, synchronization processing is performed to detect a frame start position and a slot start position,
The data of the frame or slot is extracted. After that, reception processing such as decoding is performed.

In addition to the above, there is a superframe configuration in which a superframe is formed by a plurality of frames as a configuration of digital data. In that case, the superframe of digital data by the TDMA method and the FDMA
The position on the time axis relative to the superframe of digital data according to the method can be fixed.

As described above, according to the second embodiment, the digital data slot and the F
Since the relative position on the time axis with respect to the frame of digital data by the DMA method is fixed, the TDMA
Even when the access method is switched between the FDMA method and the FDMA method, the start position of the switched access method slot or frame can be easily detected from the relative relationship between the TDMA method slot and the FDMA method frame. This makes it possible to easily execute the synchronization process.

According to the second embodiment, the FDM
Since the frame length of the digital data according to the A system is set to be the same as the frame length of the digital data according to the TDMA system, an effect is obtained that the synchronization processing can be easily executed.

Further, according to the second embodiment, the TD
Superframe of digital data by MA method and F
Since the position on the time axis relative to the superframe of the digital data by the DMA method is fixed,
Similarly, even when the access method is switched between the TDMA method and the FDMA method, the start position of the superframe of the access method after the switching can be simply determined from the relative relationship between the slot of the TDMA method and the superframe of the FDMA method. And the synchronization processing can be easily executed.

That is, in the digital mobile communication system, since the geometric positional relationship between the mobile station and the base station changes every moment, it is necessary to periodically execute the synchronization processing.
Synchronous processing is also performed at the time of handover. As described above, the synchronization process is a process that is frequently performed in digital mobile communication, and simplification of this process is a major issue as well as improvement in synchronization accuracy. If the accuracy of the synchronization processing is not good, there is a possibility that a problem such as a data error occurring in the subsequent reception processing may occur. Therefore, in the second embodiment, the synchronization processing is made simple and accurate as described above.

Embodiment 3 In digital mobile communication, transmission errors occur in transmitted digital data due to fading on a wireless transmission path or the like. Therefore, it is necessary to perform the above-described baseband processing on transmitted / received data regardless of the access method. Therefore, the mobile station 4 of the digital mobile communication system according to the third embodiment performs common baseband processing on digital data transmitted by the TDMA method and digital data transmitted by the FDMA method, and
Digital data and FDM received by MA method
A common baseband process is performed on digital data received by the A method.

FIG. 5 is a block diagram showing a configuration of the mobile station 4 of the digital mobile communication system according to the third embodiment of the present invention. In FIG. 5, reference numeral 13 denotes a baseband processing unit similar to the baseband processing units 13-1 and 13-2, which performs common baseband processing on digital data based on the TDMA system and digital data based on the FDMA system. Note that other configurations are the same as those according to the first embodiment, and a description thereof will not be repeated.

Next, the operation will be described. Baseband processing for digital data such as transmitted audio data and control data is executed by the baseband processing unit 13 regardless of the access method. Further, the baseband processing for the received digital data is also executed by the baseband processing unit 13 regardless of the access method.

The other operation is the same as that of the first embodiment, and the description is omitted.

In the third embodiment, all the baseband processes are commonly executed regardless of the access method. However, only a part of the baseband processes may be commonly executed. Good.

As described above, according to the third embodiment, the base band processing is executed in common for digital data transmitted by the TDMA method and digital data transmitted by the FDMA method, and reception is performed by the TDMA method. Since the baseband processing is executed in common for the digital data obtained and the digital data received by the FDMA method, it is possible to obtain an effect that the circuit scale can be reduced and the digital data can be produced at low cost.

Embodiment 4 FIG. 6 is a diagram showing an example of a zone configuration of a digital mobile communication system according to Embodiment 4 of the present invention. In FIG. 6A, 5-1 is TDMA
The zone of the TDMA base station 2-1 is the same as that of the base station 2, and 6-1 to 6-4 are the FDM zones similar to the FDMA base station 3.
Zones of A base stations 3-1 to 3-4. In FIG. 6B, 5-2 and 5-3 are zones of the TDMA base stations 2-2 and 2-3 similar to the TDMA base station 2,
5 and 6-6 are zones of FDMA base stations 3-5 and 3-6 similar to the FDMA base station 3. The configuration of each station in the digital mobile communication system is the same as that in the first embodiment, and a description thereof will be omitted.

Next, the operation will be described. First, FIG.
In the case of the zone configuration shown in (a), the zone 5-1 and the zones 6-1 to 6-4 overlap. That is, the zone 5-1 of the TDMA base station 2-1 which is a large zone is subdivided, and each of the subdivided areas is divided into the FDMA base station 3-
Covered by zones 6-1 to 6-4 of 1-3 to 4-4. In the overlapping zone in which the zone 5-1 and the zones 6-1 to 6-4 overlap, the mobile station 4 transmits the TDMA base station 2
-1 or any of the FDMA base stations 3-1 to 3-4 can be wirelessly communicated.

Now, when traffic is not congested, the mobile station 4 executes radio communication with the TDMA base station 2-1 in the zone 5-1 when located in the zone 5-1. . On the other hand, the mobile station 4 is transferred from an area other than the TDMA zone 5-1 to, for example, the zone 6-1 in the zone 5-1.
Has moved, the traffic locally increases in the zone 5-1 and wireless communication with the TDMA base station 2-1 becomes difficult, which may cause a communication failure. At this time, the control station 1 controls the mobile station 4 to switch to wireless communication with the FDMA base station 3-1.

As described above, the control station 1 controls to appropriately use the TDMA system and the FDMA system according to the traffic in the service area. TD according to traffic
As a method of selectively using the MA system and the FDMA system,
For example, if the traffic volume is larger than a predetermined value, T
A method of selecting the DMA method and selecting the FDMA method when the traffic volume is equal to or less than a predetermined value can be considered.

Next, in the case of the zone configuration shown in FIG. 6B, zones 5-2 and 5 of the TDMA base stations 2-2 and 2-3 are used.
-3 are not covered by FDMA base stations 3-5.
It is covered by zones 6-5 and 6-6 of 3-6. For example, in a service area including a plain area and a mountain area, the plain area is divided into zones 5-2 and 5 of the TDMA base stations 2-2 and 2-3.
-3, and the mountainous areas where radio waves do not reach from the TDMA base stations 2-2 and 2-3 are individually covered by the FDMA base station 3-
Cover with zones 6-5 and 6-6 of 5,3-6.

It is assumed that the mobile station 4 is located in the zone 5-2 of the TDMA base station 2-2 and is communicating with the TDMA base station 2-2. Thereafter, when the mobile station 4 moves to the zone 6-5 of the FDMA base station 3-5, for example, the control station 1 switches the mobile station 4 to communicate with the FDMA base station 3-5. Control.

As described above, according to the fourth embodiment, the control station 1 determines that the mobile station 4 has the zone 5-1 of the TDMA base station 2-1 and the zone 5-1 of the FDMA base stations 3-1 to 3-4. In the case where the mobile station exists in the overlapping zone 6-1 to 6-4, the TDMA system or the FDMA system is selected according to the traffic, so that the possibility of occurrence of a communication failure due to traffic congestion can be reduced. The effect that it can be obtained is obtained.

According to the fourth embodiment, TDMA base stations 3-2 and 3-3 in a certain service area
Areas other than the zones 5-2 and 5-3 of the FDMA base stations 3-5 and 3-6 are configured by the zones 6-5 and 6-6. According to the environment, the entire service area can be efficiently covered with the zone of the TDMA base station or the FDMA base station, and the effect of improving the reliability of communication can be obtained.

[0055]

As described above, according to the present invention, TD
TDMA base station for transmitting and receiving digital data by MA method and FD for transmitting and receiving digital data by FDMA method
In the service area where the MA base station and the mobile station coexist,
In the TDMA base station zone, TDM
Since digital data is transmitted / received to / from the A base station and digital data is transmitted / received to / from the FDMA base station by the FDMA method in the FDMA base station zone,
There is an effect that it is possible to construct a digital mobile communication system utilizing the features of each of the two different access systems, the TDMA system and the FDMA system.

According to the present invention, the relative position on the time axis between the digital data slot according to the TDMA system and the frame of the digital data according to the FDMA system is fixed. Even when the access method is switched between
It is possible to easily detect the start position of the slot or frame of the access method after switching from the relative relationship between the slot of the method and the frame of the FDMA method, and has the effect that the synchronization processing can be easily executed. .

According to the present invention, the relative position on the time axis between the superframe of digital data by the TDMA system and the superframe of digital data by the FDMA system is fixed, so that the TDMA system and the FDMA system are fixed. Even when the access method is switched between the above, the start position of the switched access method superframe can be easily detected from the relative relationship between the TDMA method slot and the FDMA method superframe, and There is an effect that the processing can be easily executed.

According to the present invention, since the frame length of the digital data by the FDMA system is configured to be the same as the frame length of the digital data by the TDMA system, there is an effect that the synchronization processing can be easily executed. .

According to the present invention, the base band processing is performed in common on the digital data transmitted by the TDMA method and the digital data transmitted by the FDMA method, and the digital data received by the TDMA method and the FDMA method are used. Since the mobile station has a baseband processing unit that commonly performs baseband processing on received digital data, there is an effect that the circuit scale can be reduced and the digital data can be created at low cost.

According to the present invention, since the zone of the TDMA base station and the zone of the FDMA base station are configured to overlap at least partially, it is possible to reduce the possibility of causing a communication failure due to traffic congestion. There is an effect that can be.

According to the present invention, the control station and the mobile station
If it exists in the overlapping zone of the zone of the DMA base station and the zone of the FDMA base station, the TDMA
Since the configuration is such that the system or the FDMA system is selected, there is an effect that the possibility of occurrence of a communication failure due to traffic congestion can be reduced.

According to the present invention, the control station selects the TDMA system when the traffic volume is larger than the predetermined value, and selects the FDM system when the traffic volume is smaller than the predetermined value.
Since the configuration is such that the A method is selected, there is an effect that the possibility of occurrence of a communication failure due to traffic congestion can be reduced.

According to the present invention, an area other than the zone of the TDMA base station among the fixed service areas is
Since the system is configured with MA base station zones, the entire service area can be efficiently covered with TDMA base stations or FDMA base stations according to the radio wave environment and geographical environment of the service area to improve communication reliability. There is an effect that can be.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a configuration of a mobile station in the digital mobile communication system according to the first embodiment.

FIG. 3 is a block diagram showing a configuration of a baseband processing unit of the mobile station in FIG.

FIG. 4 is a diagram showing an example of a correspondence relationship between a slot configuration of a TDMA scheme and a frame configuration of an FDMA scheme used in a digital mobile communication system according to a second embodiment of the present invention.

FIG. 5 is a block diagram showing a configuration of a mobile station in a digital mobile communication system according to Embodiment 3 of the present invention.

FIG. 6 is a diagram showing an example of a zone configuration of a digital mobile communication system according to a fourth embodiment of the present invention.

[Explanation of symbols]

1 control station, 2, 2-1 to 2-3 TDMA base station,
3,3-1-3-6 FDMA base station, 4 mobile station, 1
3 Baseband processing unit.

Continued on the front page F term (reference) 5K022 AA01 AA11 AA24 AA35 FF02 5K028 AA07 AA15 BB04 CC02 CC05 DD01 DD02 EE05 EE08 HH00 KK12 LL12 MM04 MM08 MM12 RR02 SS02 SS12 SS23 TT03 5K067 AA04 EE02 EE02 EE02

Claims (10)

[Claims] 1. A digital mobile communication system for wirelessly transmitting and receiving digital data between a base station and a mobile station, comprising: a TDMA system for transmitting and receiving digital data by a TDMA method.
FDMA for transmitting and receiving digital data by FDMA method with a base station
Digital data is transmitted and received between the base station and the TDMA base station in the TDMA base station zone by the TDMA method, and digital data is transmitted and received between the base station and the FDMA base station by the FDMA method in the FDMA base station zone. And a control station for establishing a line with the mobile station via one of the plurality of TDMA base stations and the FDMA base station. 2. The digital mobile communication system according to claim 1, wherein a relative position on a time axis between a digital data slot based on the TDMA system and a frame of digital data based on the FDMA system is fixed. 3. The digital mobile communication system according to claim 1, wherein a relative position on a time axis between a superframe of digital data based on TDMA and a superframe of digital data based on FDMA is fixed. 4. The digital mobile communication system according to claim 1, wherein the frame length of the digital data according to the FDMA system is the same as the frame length of the digital data according to the TDMA system. 5. A mobile station commonly performs baseband processing on digital data transmitted by the TDMA method and digital data transmitted by the FDMA method, and performs digital data received by the TDMA method and the FDMA method. 2. The digital mobile communication system according to claim 1, further comprising a baseband processing unit that commonly performs a baseband process on the received digital data. 6. The digital mobile communication system according to claim 1, wherein the zone of the TDMA base station and the zone of the FDMA base station overlap at least partially. 7. The control station, when the mobile station exists in an overlapping zone of the zone of the TDMA base station and the zone of the FDMA base station, uses the TDMA system or the FDM according to the traffic.
The digital mobile communication system according to claim 6, wherein the A method is selected. 8. The control station selects a TDMA system when the traffic volume is larger than a predetermined value, and selects an FDMA system when the traffic volume is equal to or less than the predetermined value. A digital mobile communication system according to claim 1. 9. The method according to claim 1, wherein the TDMA
The digital mobile communication system according to claim 1, wherein an area other than the zone of the base station is configured by a zone of the FDMA base station. 10. A digital mobile communication method for wirelessly transmitting and receiving digital data between a base station and a mobile station, comprising the steps of:
In a service area in which a base station and an FDMA base station that transmits and receives digital data by the FDMA method are mixed, a mobile station transmits and receives digital data to and from the TDMA base station by the TDMA method in the TDMA base station zone, A digital mobile communication method, wherein digital data is transmitted to and received from the FDMA base station in the zone of the FDMA base station by an FDMA scheme.