JP3312718B2 - Code division multiple access method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to wireless communication using spread spectrum.

[0002]

2. Description of the Related Art FIG. 9 is a block diagram showing a conventional radio communication access apparatus, and shows an apparatus configuration for providing services of both circuit-switched radio communication and packet-switched radio communication. This device is a circuit-switched wireless communication base station 93 to which a circuit-switched wireless communication mobile terminal 91 is wirelessly connected.
And a packet-switched wireless communication base station 94 to which a packet-switched wireless communication mobile terminal 92 is wirelessly connected. The circuit-switched wireless communication base station 93 is connected to a fixed communication network 97 via a circuit switch 95, The packet-switched wireless communication base station 94 is connected to a fixed communication network 97 via a network gateway 96. In the traffic of the circuit-switched wireless communication, the uplink is accessed from the circuit-switched wireless communication mobile terminal 91 to the fixed communication network 97 via the circuit-switched wireless communication base station 93 and the circuit switch 95, and the downlink is fixed communication. The network 97 accesses the circuit-switched wireless communication mobile terminal 91 through the circuit switch 95 and the circuit-switched wireless communication base station 93. In the traffic of the packet radio communication, the uplink is accessed from the mobile terminal 92 for packet switching radio communication to the fixed communication network 97 via the base station 94 for packet switching radio communication and the network gateway 96, and the downlink is fixed communication network. 97 accesses the packet-switched wireless communication mobile terminal 92 via the network gateway 96 and the packet-switched wireless communication base station 94.

FIG. 10 is a diagram for explaining conventional spread code allocation in the case of performing code division multiple access by spread spectrum communication. Conventionally, when performing code division multiple access, traffic channels for circuit-switched wireless communication and traffic channels for packet-switched communication have been independently performed. Therefore, the spread codes that can be allocated are classified into spread codes for control channels and spread codes for traffic channels of circuit-switched wireless communication or traffic channels of packet-switched wireless communication. Then, when a communication request is issued from or to the mobile terminal,
One spread code is assigned to the requested communication from among the assignable spread codes. If there is no assignable spreading code, communication becomes impossible.

[0004]

However, conventionally, since code division multiplex access is performed independently in the circuit-switched communication network and the packet-switched communication network, communication cannot be realized simultaneously for both, and the base station must be connected separately. To use different mobile terminals. Further, when a communication request that is equal to or more than the number of spread codes that can be allocated occurs, communication may fail because there is no spread code to allocate.

[0005] The present invention that such problems to resolve such and <br/> provide either code division multiple access method capable of performing a code division multiplex communication with the circuit-switched communications and packet-switched communication Aim.

[0006]

In sign-division multiple access method of problem solving means for the present invention, the traffic channel circuit-switched wireless communication, and the traffic channel packet-switched wireless communications, a control channel, it assigns different spreading codes.
As a result, service can be simultaneously provided for the circuit-switched wireless communication and the packet-switched wireless communication.

The number of spreading codes used for a traffic channel of circuit-switched wireless communication and the number of spreading codes used for a traffic channel of packet-switched wireless communication are adapted in accordance with the number of channels used in each wireless communication. It is desirable to change it. As a result, even if a communication request that is equal to or larger than the number of spread codes that can be normally assigned to one of the circuit-switched wireless communication and the packet-switched wireless communication occurs, communication becomes impossible by accommodating the spread code of the other sequence. Can be prevented. In this case, the minimum number of spreading codes used for the traffic channel of the circuit-switched wireless communication and the number of spreading codes used for the traffic channel of the packet-switched wireless communication that are not used for the other traffic channel must be secured. Is desirable.

The present invention is characterized in that different spread codes are assigned to a control channel for circuit-switched wireless communication and a control channel for packet-switched wireless communication, and both spread codes are used for both circuit-switched wireless communication and packet-switched wireless communication. a control channel for use at the same time is to further assign different spreading codes.

A code division multiple access apparatus embodying the present invention comprises a base station, a first interface unit connected to a circuit switching network, a second interface unit connected to a packet switching network, and a circuit switching radio. in a communication traffic channel, and traffic channel packet-switched wireless communication, a control channel, obtain Preparations and means for switching a spreading code to be used for communication with the mobile terminal.

As the mobile terminal wirelessly connected to the base station, a mobile terminal dedicated to circuit-switched wireless communication or a mobile terminal dedicated to packet-switched wireless communication can be used, but a mobile terminal capable of both communication can also be used. . That is, the mobile terminal device for carrying out the present invention, the traffic channel circuit-switched wireless communication, and the traffic channel packet-switched wireless communication, for a control channel, the common using a spreading code notified from the base station Rukoto comprises means for performing spread spectrum processing is desirable.

[0011]

FIG. 1 is a diagram showing an embodiment of the present invention, and shows a block configuration of a code division multiple access apparatus. This apparatus includes a base station 14 that performs multiplex wireless communication with mobile terminals 11 to 13 by performing spread spectrum using a spread code. The base station 14 is connected to a fixed communication network 17 via a circuit switch 15 and connected to a fixed communication network 17 via a network gateway 16. The mobile terminals 11 to 13 belong to one of the communication modes of accessing, such as only circuit-switched wireless communication, only packet-switched wireless communication, or both circuit-switched wireless communication and packet-switched wireless communication, depending on the communication mode. The base station 14 notifies the spreading code for the traffic channel and the spreading code for the control channel to perform communication. Here, it is assumed that the mobile terminal 11 is used for circuit-switched wireless communication, the mobile terminal 12 can be used for both circuit-switched wireless communication and packet-switched wireless communication, and the mobile terminal 13 is used for packet-switched wireless communication.

Regarding the spread spectrum processing performed by the mobile terminals 11 to 13, there is no difference between a traffic channel for circuit-switched wireless communication, a traffic channel for packet-switched wireless communication, and a control channel. Therefore, the mobile terminal 12 that supports both circuit-switched wireless communication and packet-switched wireless communication performs a common spectrum spreading process for each channel using the spreading code notified from the base station 14.

FIG. 2 is a diagram for explaining spreading code allocation.
Of the N spreading codes used, N _tc spreading code sequences for circuit-switched communication traffic, and _Ntc spreading code sequences for N- _{C c} spreading code sequences excluding N _c spreading codes for control channels, and traffic channels for packet-switched communication N _tp sequences are allocated for use, and a sequence spreading code corresponding to the communication mode of the generated communication request is allocated.

FIG. 3 is a diagram for explaining adaptive allocation of spreading codes. In a normal communication state, the assignment shown in FIG. 2 is performed.
The number of spreading codes that can be assigned to each traffic channel is adaptively set according to the state of the number of traffic channels used for each of the circuit-switched wireless communication and the packet-switched wireless communication. At this time, the minimum number of spreading codes used for the traffic channel of circuit-switched wireless communication and the number of spreading codes used for the traffic channel of packet-switched wireless communication that are not used for the other traffic channel must be secured. Is desirable.

FIG. 4 is a block diagram showing a configuration example of a base station. This base station comprises a code switching multiplexing between a circuit switching network interface 41 connected to a circuit switch (circuit switching network), a packet switching network interface 42 connected to a network gateway (packet switching network), and a mobile terminal. A wireless device 43 for performing communication and the wireless device 4
A spreading code controller 44 for controlling a spreading code used by the communication channel 3 and switching a sequence of spreading codes between a traffic channel for circuit-switched wireless communication, a traffic channel for packet-switched wireless communication, and a control channel;
5, 46 and spreading code assignment setting value storage devices 47, 48
And a base station controller 49 for controlling the operation of the base station.

The base station controller 49 controls the communication line with the fixed communication network through the circuit switching network interface 41 and the packet switching network interface 42, and controls the line of the wireless communication network through the wireless device 43. The base station controller 49 also requests the spreading code controller 44 to perform a procedure for allocating and releasing a spreading code in response to a communication connection request and a communication disconnection request from the wireless device 43.

The wireless device 43 communicates with the mobile terminal using the assigned spreading code.

The spreading code controller 44 allocates a spreading code to a communication request from the radio device 43, and counts the number of allocations for circuit-switched radio communication by the traffic counter 4.
5, and the traffic counter 46 counts the number assigned to the packet-switched wireless communication. The spreading code assignment setting value storage device 47 stores assignment setting values for circuit-switched wireless communication, and the spreading code assignment setting value storage device 48 stores assignment setting values for packet-switched wireless communication. The spreading code control device 44 also changes the values stored in the spreading code assignment setting value storage devices 47 and 48 based on the count values of the traffic counters 45 and 46, and changes the spread code for the traffic channel for circuit-switched wireless communication. The ratio of the spreading code for the traffic channel of the packet switching wireless communication is changed. For example, if the number of traffic channels of the circuit-switched communication used, that is, the count value of the traffic counter 45 becomes equal to the number of spreading codes of the assigned traffic channel, the spreading for the traffic channel of the packet-switched wireless communication is performed. By reducing the number of codes and increasing the number of spreading codes for the traffic channel of the circuit-switched wireless communication, a traffic channel of the circuit-switched wireless communication is secured. Similarly, when the number of traffics of the packet-switched wireless communication, that is, the count value of the traffic counter 46 becomes equal to the number of assigned spreading codes of the traffic channel, the spread for the traffic channel of the circuit-switched wireless communication is similarly determined. By reducing the number of codes and increasing the number of spreading codes for traffic channel of packet-switched wireless communication, a traffic channel of packet-switched wireless communication is secured.

Table 1 shows a specific example of allocation of spreading codes.
In this table, “the number of channels” is the number of channels actually used, and represents the count value of the traffic counters 45 and 46 shown in FIG. “Allocation setting value” is the number of sequences of spreading codes allocated as usable,
The values stored in the spreading code assignment setting value storage devices 47 and 48 shown in FIG. Here, an orthogonal m-sequence (64 chips, the number of sequences is 64) is used as a set A of spreading codes. It is assumed that eight sequences are used as control channel spreading codes, and in an initial state, 16 sequences are allocated as traffic channel spreading codes for circuit-switched wireless communication and 40 sequences are allocated as circuit switching wireless communication traffic channels. Here, it is assumed that six channels are used as traffic channels for circuit-switched wireless communication and 38 channels are used as traffic channels for packet-switched wireless communication. In this state, it is assumed that two traffic channels for circuit-switched wireless communication have been completed. At this time, the number of traffic channels of the circuit-switched wireless communication is four. Next, it is assumed that the traffic of the packet-switched wireless communication increases by two channels.
In this case, the number of traffic channels of the packet-switched wireless communication is 40. In such a case, the spreading code control device 44 changes the number of spreading code sequences to be allocated to the circuit-switched wireless communication to 15 and the number of spreading code sequences to be allocated to the packet-switched wireless communication to 41. 47 and 48.

[0020]

[Table 1]

FIG. 5 is a diagram for explaining the spread code allocation for the control channel. When controlling different communication modes such as circuit-switched wireless communication and packet-switched wireless communication, different spreading codes for control channels are assigned to the respective communication modes. Further, when a communication request for using the circuit-switched wireless communication and the packet-switched wireless communication at the same time occurs, a spread code for a control channel for commonly controlling the circuit-switched wireless communication and the packet-switched wireless communication is assigned.

FIG. 6 shows a layer configuration of a communication system according to the present invention. In layer 1, maintenance of the physical transmission medium is performed. As items common to both circuit-switched wireless communication and packet-switched wireless communication, the basic transmission rate, modulation method, synchronization method, occupied bandwidth, mobile station transmission power control, and the like are specified. Furthermore, VOX control is performed in circuit-switched wireless communication, and transmission rate allocation according to packet traffic and spread code allocation and management accompanying channel allocation are performed in packet-switched wireless communication. In the layer 2, the setting of the logical link between the nodes is maintained. As items common to both circuit-switched wireless communication and packet-switched wireless communication, logical address control of mobile stations and error detection and control of communication information are performed. Furthermore, in packet-switched wireless communication, the signal order of transmission packets is ensured, and retransmission control is performed in accordance with error detection. In layer 3, wireless management, mobility management, and call control are defined as modules. Radio management and mobility management are commonly performed for both circuit switching and packet switching. In the wireless management, selection of a serving cell, maintenance of a control line, management of failure and performance of the wireless line, and setting of concealment are performed. In the mobility management, location control of the mobile station, terminal authentication, and registration control of mobile station activation information are performed. As call control, in circuit-switched wireless communication, mobile station transmission control, mobile station termination control, and supplementary service control are performed. In packet-switched wireless communication, mobile station packet transmission control and broadcast packet control are performed.

FIG. 7 shows a control channel sequence when performing circuit-switched wireless communication, and FIG. 8 shows a control channel sequence when performing packet-switched wireless communication. Here, it is assumed that the control channels of the circuit-switched wireless communication and the packet-switched wireless communication are separated, and different control channels are assigned to them. In the control channel sequence of the circuit-switched wireless communication, a procedure for establishing a link channel, controlling a call, controlling a radio, and controlling a mobility is performed for each call when a mobile terminal originates or receives a call. Link channel establishment, code synchronization, and the like are performed on the control channel, and the control channel is released by using each traffic channel for call control, radio management, and mobility management. on the other hand,
In the control channel sequence of packet-switched wireless communication,
When the mobile terminal enters the communicable area, the procedure of link channel establishment, call control, radio management and mobility management is performed using the control channel allocated for each call. At the time of transmitting a packet, a packet transmission request and a request response procedure are exchanged, and then the packet is transmitted, so that the transmission delay associated with establishing a link channel at the time of transmitting the packet is greatly reduced. When performing circuit-switched wireless communication and packet-switched wireless communication at the same time, control information is shared using a control channel sequence of packet-switched wireless communication.

[0024]

As described above, according to the present invention,
Of the spreading codes used, a spreading code for a control channel,
A spreading code for a traffic channel of circuit-switched wireless communication,
By assigning a plurality of spreading codes to each of the traffic channel spreading codes of the packet-switched wireless communication, both communication modes can be realized simultaneously.
Furthermore, by changing the ratio of the spreading code for the traffic channel of the circuit-switched wireless communication and the spreading code for the traffic channel of the packet-switched wireless communication according to the use state of the line, the communication request of either the circuit switching or the packet switching is normally performed. Even if the number of assigned spreading codes exceeds the number, the communication is not disabled.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a view for explaining spreading code assignment.

FIG. 3 is a diagram illustrating adaptive allocation of spreading codes.

FIG. 4 is a block diagram of a base station.

FIG. 5 is a view for explaining spreading code allocation for a control channel.

FIG. 6 is a diagram showing a layer configuration of a communication system according to the present invention.

FIG. 7 is a diagram showing a control channel sequence when performing circuit-switched wireless communication.

FIG. 8 is a diagram showing a control channel sequence when performing packet-switched wireless communication.

FIG. 9 is a block diagram showing a conventional wireless communication access apparatus.

FIG. 10 is a view for explaining conventional spreading code allocation when performing code division multiple access by spread spectrum communication.

[Explanation of symbols]

 11-13 Mobile terminal 14 Base station 15,95 Circuit switch 16,96 Network gateway 17,97 Fixed communication network 41 Circuit switch network interface 42 Packet switch network interface 43 Radio equipment 44 Spreading code controller 45,46 Traffic counter 47,48 Spreading code assignment setting value storage device 49 Base station controller 91 Mobile terminal for circuit-switched wireless communication 92 Mobile terminal for packet-switched wireless communication 93 Base station for circuit-switched wireless communication 94 Base station for packet-switched wireless communication

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takeshi Hattori 3-19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Within Nippon Telegraph and Telephone Corporation (56) References JP-A-8-188682 (JP, A) JP-A-63-288540 (JP, A) JP-A-63-13535 (JP, A) JP-A-7-283763 (JP, A) Table 10-512724 (JP, A) (58) Int.Cl. ⁷ , DB name) H04Q ^7/ 00-7/38 H04B ⁷ /24-7/26

Claims (1)

(57) [Claims] 1. A traffic channel for circuit-switched wireless communication.
Traffic channels and controls for packet-switched wireless communications
Assign different spreading codes to the
The channel is assigned the spreading code assigned to that channel .
In a code division multiple access method for performing multiplex wireless communication by spreading the spectrum, a control channel for circuit-switched wireless communication and a packet-switched wireless communication are used.
If different spreading codes are assigned to the signal control channel and
In particular, both circuit-switched wireless communication and packet-switched wireless communication
Control channel for simultaneous use of
A code division multiple access method characterized by assigning a scatter code .