Mobile communication system using various multiple access methods

• US 6,009,087 A
• Filed: 05/12/1998
• Issued: 12/28/1999
• Est. Priority Date: 09/09/1994
• Status: Expired due to Term

• Current Assignee: TCL Communication Technology Holdings Ltd. (TCL Technology Group Corp.)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Ishida, Kenichi, Uchida, Yoshinori, Kashiwagi, Takashi
• Primary Examiner(s): Ngo, Ricky
• Assistant Examiner(s): Duong, Frank
• Application Number:
  US09/076,117
• Time in Patent Office: 595 Days
• Field of Search: 370/328, 370/329, 370/335, 370/336, 370/337, 370/342, 370/345, 370/347, 370/348, 370/320, 370/321, 375/200, 375/201, 375/205, 375/207, 455/33.1, 455/51.1, 455/54.1, 455/56.1
• US Class Current: 370/335
• CPC Class Codes: H04B 7/18532 Arrangements for managing transmission, i.e. for transporting data or a signalling message
• CPC Class Codes: H04J 13/10 Code generation
• CPC Class Codes: H04M 2215/32 Involving wireless systems
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/142 over the same radio air interface technology
• CPC Class Codes: H04W 4/24 Accounting or billing
• CPC Class Codes: H04W 72/56 based on priority criteria
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A mobile communication system in which various access methods may be selected according to the user'"'"'s priority. In the mobile communication system, each of a mobile station and radio base stations has a radio processor, which has TDMA, CDMA and FDMA communication units. The CDMA communication unit comprises channel coders each for performing a primary modulation to a transmitting signal, spread-spectrum code generators for respectively generating different spread-spectrum signals, a clock generator/controller for controlling the generation of chip clocks to control the generation of the spread-spectrum codes, oscillators for setting different carrier frequencies to outputs calculated as products, and a CPU for generally controlling various parts or elements to control the assignment of a CDMA signal or a TDMA signal to an arbitrary time slot transmitted from the TDMA communication unit. The radio processor transmits different signals of different access methods existing in each time slot of the same frame different signals.

Claims

1. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and at least a radio base station for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable radio stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signals or said CDMA signals to each of said time slots, and for controlling both said communication means in such manner that both said TDMA signals and said CDMA signals exist in a single frame;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generator, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

2. A mobile communication system which includes a plurality of mobile and/or portable radio stations and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots, and for controlling both said communication means in such manner that both said TDMA signals and said CDMA signals exist in a single frame;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generators, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

3. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and at least a radio base station for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable radio stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signals or said CDMA signals to each of said time slots, and for controlling the generation of time-divided CDMA signals generated from said spread-spectrum codes by said spread-spectrum code generator;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generator, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

4. A mobile communication system which includes a plurality of mobile and/or portable radio stations and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots, and for controlling the generation of time-divided CDMA signals generated from said spread-spectrum codes by said spread-spectrum code generator;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generators, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

5. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and at least a radio base station for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable radio stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signals or said CDMA signals to each of said time slots, and for determining an access method to be used for communication with another station based on an access method deciding condition and assigns signals configured according to the determined access method to a predetermined time slot;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generator, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

6. A mobile communication system which includes a plurality of mobile and/or portable radio stations and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators;

, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots, and for determining an access method to be used for communication with another station based on an access method deciding condition and assigns signals configured according to the determined access method to a predetermined time slot;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generators respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

7. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and at least a radio base station for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable radio stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signals or said CDMA signals to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generator, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots; and

(e) said CDMA communication means at each radio base station has channel coders associated with respective time slots for performing a primary modulation of transmitted information, said spread-spectrum code generator generates a different spread-spectrum code for each of said time slots, and said control means assigns said CDMA signals to said time slots based on product information of an output of each said channel coder and corresponding spread-spectrum code for each respective time slot.

8. A mobile communication system which includes a plurality of mobile and/or portable radio stations and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generators, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots; and

(e) said CDMA communication means at each radio base station has channel coders associated with respective time slots for performing a primary modulation of transmitted information, said spread-spectrum code generator generates a different spread-spectrum code for each of said time slots, and said control means assigns said CDMA signals to said time slots based on product information of an output of each said channel coder and corresponding spread-spectrum code for each respective time slot.

9. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and at least a radio base station for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable radio stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signals or said CDMA signals to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generator, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots; and

(e) said CDMA communication means has a number of channel coders associated with each of said time slots for performing a primary modulation of transmitted information, said spread-spectrum code generator generates a different spread-spectrum code for each of said time slots, and said control means assigns CDMA signals to said time slots based on product information of an output of each said channel coder and corresponding spread-spectrum code for each respective time slot so as to assign a number of channels to one of said time slots.

10. A mobile communication system which includes a plurality of mobile and/or portable radio stations and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generators, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots; and

(e) said CDMA communication means has a number of channel coders associated with each of said time slots for performing a primary modulation of transmitted information, said spread-spectrum code generator generates a different spread-spectrum code for each of said time slots, and said control means assigns CDMA signals to said time slots based on product information of an output of each said channel coder and corresponding spread-spectrum code for each respective time slot so as to assign a number of channels to one of said time slots.

11. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and at least a radio base station for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable radio stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signals or said CDMA signals to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generator, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots; and

(e) said mobile and/or portable radio stations include receiving-state detecting means for detecting a state of receiving signals from a number of said radio base stations, and said control means sets a separate communication channel between the mobile and/or portable station and another radio base station using a time slot different from the time slot presently occupied as a communication channel between the mobile and/or portable radio station and radio base station, based on the detected receiving state.

12. A mobile communication system which includes a plurality of mobile and/or portable radio stations and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generators, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots; and

(e) said mobile and/or portable radio stations include receiving-state detecting means for detecting a state of receiving signals from a number of said radio base stations, and said control means sets a separate communication channel between the mobile and/or portable station and another radio base station using a time slot different from the time slot presently occupied as a communication channel between the mobile and/or portable radio station and radio base station, based on the detected receiving state.

13. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and radio base stations for performing wireless communication between said mobile stations and said base stations using a predetermined method selected from a number of multiple access methods, each of said mobile and/or portable radio stations and radio base stations comprising:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and means for generating an empty time slot;

(c) said CDMA communication means being adapted for assigning time-divided spread-spectrum signals, which are obtained with different spread-spectrum codes generated by said spread-spectrum code generators, respectively to said time slots of said TDMA communication method, whereby communication is carried out in such a manner that both TDMA signals and CDMA signals exist in said time slots; and

(d) control means for selecting one of said TDMA method and said CDMA method for carrying out communication.

14. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and radio base stations for performing wireless communication between said mobile stations and said base stations using a predetermined method selected from a number of multiple access methods, each of said mobile and/or portable radio stations and radio base stations comprising:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and means for generating an empty time slot;

(c) said CDMA communication means being adapted for assigning time-divided spread-spectrum signals, which are obtained with different spread-spectrum codes generated by said spread-spectrum code generators, respectively to said time slots of said TDMA method, whereby communication is carried out in such a manner that both TDMA signals and CDMA signals exist in said time slots; and

(d) control means for selecting one of said TDMA method and said CDMA method for carrying out communication.

15. A mobile communication system which includes, a plurality of mobile and/or portable radio stations, and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having at least one spread-spectrum code generator and adapted for communication of CDMA signals based on a CDMA method, and means for generating an empty time slot; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided spread-spectrum signals, which are generated by said spread-spectrum code generator, to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

16. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and at least a radio base station for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable radio stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and means for generating an empty time slot; and

(c) control means for controlling each said station to selectively assign said TDMA signals or said CDMA signals to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generator, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

17. A mobile communication system which includes a plurality of mobile and/or portable radio stations and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and means for generating an empty time slot; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generators, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

18. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and radio base stations for performing wireless communication between said mobile stations and said base stations using a predetermined method selected from a number of multiple access methods, each of said mobile and/or portable radio stations and radio base stations comprising:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and having an initial value setting unit for arbitrarily setting an initial value of the spread-spectrum code generated by said spread-spectrum code generators;

(c) said CDMA communication means being adapted for assigning time-divided spread-spectrum signals, which are obtained with different spread-spectrum codes generated by said spread-spectrum code generators, respectively to said time slots of said TDMA communication method, whereby communication is carried out in such a manner that both TDMA signals and CDMA signals exist in said time slots; and

(d) control means for selecting one of said TDMA method and said CDMA method for carrying out communication.

19. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and radio base stations for performing wireless communication between said mobile stations and said base stations using a predetermined method selected from a number of multiple access methods, each of said mobile and/or portable radio stations and radio base stations comprising:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and having an initial value setting unit for arbitrarily setting an initial value of the spread-spectrum code generated by said spread-spectrum code generators;

(c) said CDMA communication means being adapted for assigning time-divided spread-spectrum signals, which are obtained with different spread-spectrum codes generated by said spread-spectrum code generators, respectively to said time slots of said TDMA method, whereby communication is carried out in such a manner that both TDMA signals and CDMA signals exist in said time slots; and

(d) control means for selecting one of said TDMA method and said CDMA method for carrying out communication.

20. A mobile communication system which includes, a plurality of mobile and/or portable radio stations, and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having at least one spread-spectrum code generator and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided spread-spectrum signals, which are generated by said spread-spectrum code generator, to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots, and having an initial value setting unit for arbitrarily setting an initial value of the spread-spectrum code generated by said spread-spectrum code generators.

21. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and at least a radio base station for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable radio stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and having an initial value setting unit for arbitrarily setting an initial value of the spread-spectrum code generated by said spread-spectrum code generators; and

(c) control means for controlling each said station to selectively assign said TDMA signals or said CDMA signals to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generator, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

22. A mobile communication system which includes a plurality of mobile and/or portable radio stations and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and having an initial value setting unit for arbitrarily setting an initial value of the spread-spectrum code generated by said spread-spectrum code generators; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generators, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

23. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and radio base stations for performing wireless communication between said mobile stations and said base stations using a predetermined method selected from a number of multiple access methods, each of said mobile and/or portable radio stations and radio base stations comprising:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and having a spread-spectrum code value setting unit for arbitrarily setting a value of the spread-spectrum code generated by said spread-spectrum code generators, by a generating polynomial;

(c) said CDMA communication means being adapted for assigning time-divided spread-spectrum signals, which are obtained with different spread-spectrum codes generated by said spread-spectrum code generators, respectively to said time slots of said TDMA communication method, whereby communication is carried out in such a manner that both TDMA signals and CDMA signals exist in said time slots; and

(d) control means for selecting one of said TDMA method and said CDMA method for carrying out communication.

24. A mobile communication system according to claim 23, wherein said spread-spectrum code value setting unit has a group of switches for freely changing a feedback loop including a shift register.

25. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and radio base stations for performing wireless communication between said mobile stations and said base stations using a predetermined method selected from a number of multiple access methods, each of said mobile and/or portable radio stations and radio base stations comprising:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and having a spread-spectrum code value setting unit for arbitrarily setting a value of the spread-spectrum code generated by said spread-spectrum code generators, by a generating polynomial;

(c) said CDMA communication means being adapted for assigning time-divided spread-spectrum signals, which are obtained with different spread-spectrum codes generated by said spread-spectrum code generators, respectively to said time slots of said TDMA method, whereby communication is carried out in such a manner that both TDMA signals and CDMA signals exist in said time slots; and

(d) control means for selecting one of said TDMA method and said CDMA method for carrying out communication.

26. A mobile communication system according to claim 25, wherein said spread-spectrum code value setting unit has a group of switches for freely changing a feedback loop including a shift register.

27. A mobile communication system which includes, a plurality of mobile and/or portable radio stations, and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having at least one spread-spectrum code generator and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided spread-spectrum signals, which are generated by said spread-spectrum code generator, to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots, and having a spread-spectrum code value setting unit for arbitrarily setting a value of the spread-spectrum code generated by said spread-spectrum code generators, by a generating polynomial.

28. A mobile communication system according to claim 27, wherein said spread-spectrum code value setting unit has a group of switches for freely changing a feedback loop including a shift register.

29. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and at least a radio base station for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable radio stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and having a spread-spectrum code value setting unit for arbitrarily setting a value of the spread-spectrum code generated by said spread-spectrum code generators, by a generating polynomial; and

(c) control means for controlling each said station to selectively assign said TDMA signals or said CDMA signals to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generator, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

30. A mobile communication system according to claim 29, wherein said spread-spectrum code value setting unit has a group of switches for freely changing a feedback loop including a shift register.

31. A mobile communication system which includes a plurality of mobile and/or portable radio stations and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and having a spread-spectrum code value setting unit for arbitrarily setting a value of the spread-spectrum code generated by said spread-spectrum code generators, by a generating polynomial; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generators, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

32. A mobile communication system according to claim 31, wherein said spread-spectrum code value setting unit has a group of switches for freely changing a feedback loop including a shift register.

33. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and at least a radio base station for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable radio stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and having a chip clock control unit for controlling a chip clock of said spread-spectrum code generator; and

(c) control means for controlling each said station to selectively assign said TDMA signals or said CDMA signals to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generator, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

34. A mobile communication system which includes a plurality of mobile and/or portable radio stations and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and adapted for communication of CDMA signals based on a CDMA method, and having a chip clock control unit for controlling a chip clock of said spread-spectrum code generator; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generators, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

35. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and at least a radio base station for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable radio stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and adapted for communication of CDMA signals based on a CDMA method, and having a chip rate control unit for controlling a chip rate of said spread-spectrum code generator; and

(c) control means for controlling each said station to selectively assign said TDMA signals or said CDMA signals to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generator, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

36. A mobile communication system which includes a plurality of mobile and/or portable radio stations and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method, and having a chip rate control unit for controlling a chip rate of said spread-spectrum code generator; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots;

(d) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generators, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

37. A mobile communication system which includes a plurality of mobile and/or portable radio stations, and at least a radio base station for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable radio stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a spread-spectrum code generator, which generates a number of spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signals or said CDMA signals to each of said time slots;

(d) a carrier frequency control unit for controlling a carrier frequency of each time slot;

(e) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generator, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.

38. A mobile communication system which includes a plurality of mobile and/or portable radio stations and radio base stations for performing wireless communication between said stations using a predetermined method selected from a number of multiple access methods, wherein each of said mobile and/or portable stations and radio base stations comprises:

(a) TDMA communication means for assigning TDMA signals to time slots, which are contained in a frame, to perform communication based on a TDMA method;

(b) CDMA communication means having a number of spread-spectrum code generators, which generate different spread-spectrum codes, and adapted for communication of CDMA signals based on a CDMA method; and

(c) control means for controlling each said station to selectively assign said TDMA signal or said CDMA signal to each of said time slots;

(d) a carrier frequency control unit for controlling a carrier frequency of each time slot;

(e) said CDMA communication means being adapted for assigning time-divided CDMA signals created by different spread-spectrum codes, which are generated by said spread-spectrum code generators, respectively to said time slots in such a manner that both said TDMA and CDMA signals exist in said time slots.