Mobile communication system and a method thereof

• US 6,477,159 B1
• Filed: 07/06/1999
• Issued: 11/05/2002
• Est. Priority Date: 07/06/1998
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Yahagi, Masahiko
• Primary Examiner(s): Bost, Dwayne
• Assistant Examiner(s): West, Lewis G.
• Application Number:
  US09/347,453
• Time in Patent Office: 1,218 Days
• Field of Search: 455/437, 455/442, 455/434, 455/450, 455/452, 455/511, 370/332, 370/335, 370/342, 375/140, 375/149
• US Class Current: 370/335
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 36/00692 using simultaneous multiple data streams, e.g. cooperative multipoint [CoMP], carrier aggregation [CA] or multiple input multiple output [MIMO] allocation of physical resources in CoMP or in CA H04L5/0035
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 76/11 Allocation or use of connection identifiers

Abstract

A mobile communication system and its method, which uses a discrimination code specific to a mobile terminal as an discriminating signal for both of reverse channel and forward channel between a mobile terminal and a mobile communication network, are provided. A mobile terminal includes a predetermined modulating and demodulating code generator, and makes a call connection request through an access channel based on broadcast information from a base station. The call connection request contains an equipment number of the mobile terminal, and based on this equipment number, the network side device discriminates a code corresponding to this mobile terminal. The base station modulates and demodulates a reverse channel and forward channel signals based on the discriminated code.

Claims

1. A mobile communication system comprising:

a mobile communication network; and

a mobile terminal device which performs communications with said mobile communication network, said mobile communication network including a plurality of base stations and a base station control equipment by a code division multiple access (CDMA) system,

wherein said mobile terminal comprises;

a call connection requesting part for transmitting, through a predetermined control channel, a call connection request signal by adding specific information provided for said mobile terminal;

a transmitting part for diffusing and modulating a transmitting signal of a reverse channel transmitted from said mobile terminal to each of said base stations based on a transmission diffusing code specified by said specific information provided for said mobile terminal; and

a receiving part for oppositely-diffusing and demodulating a received signal of a forward channel transmitted from each of said base stations to said mobile terminal based on a receiving oppositely-diffusing code specified by said specific information provided for said mobile terminal; and

wherein said mobile communication network further comprises;

a translating part for translating said specific information provided for said mobile terminal, which is contained in said call connection request signal received through said control channel, and extracting a diffusing code used for each of said reverse channel and forward channel for said mobile terminal;

a transmitting part for diffusing and modulating a transmitted signal based on said forward channel transmission diffusing code extracted by said translating part; and

a receiving part for oppositely-diffusing and demodulating a received signal based on said reverse channel receiving oppositely-diffusing code extracted by said translating part.

2. A mobile communication system according to claim 1, wherein said mobile terminal further comprises a monitoring part for measuring, based on information regarding each of said base stations adjacent to one another, which is notified beforehand, a receiving level of radio signals emitted from each of said adjacent base stations, and then reporting said measured receiving level to said each of base stations, and

wherein said mobile communication network further comprises a hand-over control part for notifying a base station of said oppositely-diffusing and diffusing codes for said reverse channel and forward channel for said mobile terminal, said base station being one where a receiving level of radio signals emitted from each of said adjacent base stations, which is reported from said mobile terminal, reaches a predetermined value, and then instructing starting of communications with said mobile terminal.

3. A mobile communication system according to claim 1, wherein said specific information comprises a unique equipment number provided for said mobile terminal.

4. A mobile communication method in which a mobile terminal performs communications with a mobile communication network including a plurality of base stations and a base station control equipment by a code division multiple access (CDMA) system, the method comprising:

in said mobile terminal,

transmitting a call connection request signal through a predetermined control channel by adding specific information provided for said mobile terminal;

diffusing and modulating a transmitted signal of a reverse channel going from said mobile terminal to each of said base stations based on a transmission diffusing code specified by said specific information provided for said mobile terminal;

oppositely-diffusing and demodulating a received signal of a forward channel going from each of said base stations to said mobile terminal based on a receiving oppositely-diffusing code specified by said specific information provided for said mobile terminal;

measuring, during communications, a receiving level of a radio signal emitted from each of said base stations adjacent to one another based on information regarding each of said adjacent base stations, which is notified beforehand; and

reporting a result of said measuring to each of said base stations; and

in said mobile communication network,

translating said specific information provided for said mobile terminal, which is contained in said call connection request signal received through said control channel;

extracting a diffusing code used for each of said reverse channel and forward channel for said mobile terminal;

diffusing and modulating a transmitted signal based on said extracted forward channel transmission diffusing code;

oppositely diffusing and demodulating a received signal based on said extracted reverse channel receiving oppositely-diffusing code;

notifying a base station of said oppositely diffusing code for said reverse channel and said diffusing code for said forward channel for said mobile terminal, said base station being one where a receiving level of a radio signal emitted from each of said adjacent base stations, which is reported from said mobile terminal, reaches a predetermined value; and

instructing starting of communications with said mobile terminal.

5. A mobile communication method according to claim 4, wherein said specific information comprises a unique equipment number provided for said mobile terminal.

6. A mobile terminal for a mobile communication system including a plurality of base stations and a base station control equipment, the mobile terminal comprising:

a call connection requesting part for transmitting a call connection request signal by adding specific information provided for said mobile terminal;

a transmitting part for diffusing and modulating a transmitting signal of a reverse channel transmitted from said mobile terminal to each of said plurality of base stations based on a transmission diffusing code specified by said specific information provided for said mobile terminal; and

a receiving part for oppositely-diffusing and demodulating a received signal of a forward channel transmitted from each of said plurality of base stations to said mobile terminal based on a receiving oppositely-diffusing code specified by said specific information provided for said mobile terminal.

7. A mobile communication system, incorporating the mobile terminal of claim 6, further comprising:

a mobile communication network which communicates with said mobile terminal device, said mobile communication network comprising;

a translating part for translating said specific information provided for said mobile terminal, which is contained in said call connection request signal received through said control channel, and extracting a diffusing code used for each of said reverse channel and forward channel for said mobile terminal;

a transmitting part for diffusing and modulating a transmitted signal based on said forward channel transmission diffusing code extracted by said translating part; and

a receiving part for oppositely-diffusing and demodulating a received signal based on said reverse channel receiving oppositely-diffusing code extracted by said translating part.

8. The mobile terminal, as claimed in claim 6, wherein said specific information comprises a unique equipment number provided for said mobile terminal.

9. A mobile communication network which communicates with a mobile terminal device, said mobile communication network comprising:

a translating part for translating a specific information provided for said mobile terminal device, where the specific information for is contained in a call connection request signal received through a control channel, and for extracting a diffusing code used for each of a reverse channel and a forward channel for said mobile terminal device;

a transmitting part for diffusing and modulating a transmitted signal based on said forward channel diffusing code extracted by said translating part; and

a receiving part for oppositely-diffusing and demodulating a received signal based on said reverse channel receiving an oppositely-diffusing code extracted by said translating part.

10. A code division multiple access (CDMA) communication system comprising:

a mobile terminal which uses a diffusing code specific to said mobile terminal for both a reverse channel and a forward channel,

wherein said diffusing code is determined based upon specific information provided for said mobile terminal.

11. The CDMA communication system according to claim 10, wherein said specific information comprises a unique equipment number provided for said mobile terminal.

12. A code division multiple access (CDMA) communication method for a communication system including a mobile terminal, said method comprising:

using a diffusing code specific to said mobile terminal for both a reverse channel and a forward channel.

13. The CDMA communication method according to claim 12, further comprising:

determining said diffusing code specific to said mobile terminal based upon specific information provided for said mobile terminal.

14. The CDMA method according to claim 13, wherein said specific information comprises a unique equipment number provided for said mobile terminal.