Radio paging system

• US 5,736,934 A
• Filed: 11/05/1996
• Issued: 04/07/1998
• Est. Priority Date: 01/28/1993
• Status: Expired due to Term

• Current Assignee: NTT Mobile Communications Network Inc. (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Mobile Communications Network Inc. (Nippon Telegraph and Telephone Corporation)
• Inventors: Hirai, Yoshiaki, Ito, Shogo, Nozawa, Toshihiro
• Primary Examiner(s): ZIMMERMAN, BRIAN A
• Application Number:
  US08/742,703
• Time in Patent Office: 518 Days
• Field of Search: 340/825.44, 340/825.47
• US Class Current: 340/7.43
• CPC Class Codes: H04W 88/187 using digital or pulse address codes

Abstract

In a mobile radio communication system wherein mobile units are paged by repeatedly transmitting the same paging signal in n paging signal frames, the number of times a paging signal has been transmitted can be known at the receiving side without the need to transmit additional information, and a time diversity reception scheme can be employed at the receiving side, by forming the paging signal frames from n fixed-length subframes each of which contains a paging signal, and by positioning subframes that contain a new paging signal at one end of the paging signal frames, and, in the case of subframes containing paging signals that will be transmitted for the second or subsequent time, by arranging such subframes with a stagger in accordance with this number of times.

Claims

1. A mobile radio communication system comprising:

a plurality of pagers; and

a base station for transmitting a plurality of paging signal frames to said plurality of pagers via at least one radio channel, each of said plurality n of paging signal frames including a plurality n of fixed-length subframes, n being a natural number, a first of said plurality n of fixed-length subframes being closest to a synchronization signal from said base station and an n^th of said plurality n of fixed-length subframes being farthest from said synchronization signal, each of said plurality n of fixed-length subframes containing a plurality of paging signals each having an address signal indicating a unique address corresponding to at least one of said plurality of pagers associated therewith, said base station including repeated transmitting means for transmitting a same paging signal in each of said plurality of paging signal frames, said repeated transmitting means comprising;

new paging signal inserting means for inserting a new paging signal to be transmitted by said base station for a first time into said first one of said plurality n fixed-length subframes, and

repeated paging signal inserting means for inserting a repeated paging signal to be transmitted by said base station for at least a second time into one of said n fixed-length subframes positioned according to a number of times that said repeated paging signal is to be transmitted by said base station, said repeated paging signal being positioned differently for each transmission thereof.

2. A mobile radio communication system according to claim 1, wherein:

said repeated paging signal inserting means removes said repeated paging signal from one of said n fixed-length subframes positioned one less than said number of times that said repeated paging signal is to be transmitted currently by said base station.

3. A pager in a mobile radio communication system, said pager comprising:

a receiver for receiving a plurality of paging signal frames from a base station transmitted via at least one radio channel, each of said plurality n of paging signal frames including a plurality n of fixed-length subframes, n being a natural number, a first of said plurality n of fixed-length subframes being closest to a synchronization signal from said base station and an n^th of said plurality n of fixed-length subframes being farthest from said synchronization signal, each of said plurality n of fixed-length subframes containing a plurality of paging signals each having an address signal indicating a unique address corresponding to at least one of said plurality of pagers associated therewith, said at least one of said plurality of pagers including repeated receiving means for receiving a same paging signal in each of said plurality of paging signal frames, said repeated receiving means comprising;

new paging signal receiving means for receiving a new paging signal transmitted by said base station for a first time in said first one of said plurality n fixed-length subframes, and

repeated paging signal receiving means for receiving a repeated paging signal transmitted by said base station for at least a second time in one of said n fixed-length subframes positioned according to a number of times that said repeated paging signal has been transmitted by said base station, said repeated paging signal being positioned differently for each transmission thereof.

4. A pager in a mobile radio communication system according to claim 3, wherein said repeated receiving means further comprises:

means for storing said new paging signal;

means for developing reliability information based on said stored new paging signal; and

means for using said developed reliability information to perform bit decision on said repeated paging signal.

5. A pager in a mobile radio communication system according to claim 3, wherein said repeated receiving means further comprises:

means for storing said new paging signal and said repeated paging signal;

means for developing reliability information based on said stored new paging signal and said repeated paging signal; and

means for using said developed reliability information to perform bit decision on said paging signal each time received by said receiver subsequent to said at least said second time.

6. A method of communicating repeatedly a paging signal from a base station to at least one of a plurality of pagers, said method comprising steps of:

transmitting from said base station a plurality of paging signal frames to said plurality of pagers via at least one radio channel, each of said plurality n of paging signal frames including a plurality n of fixed-length subframes, n being a natural number, a first of said plurality n of fixed-length subframes being closest to a synchronization signal from said base station and an n^th of said plurality n of fixed-length subframes being farthest from said synchronization signal, each of said plurality n of fixed-length subframes containing a plurality of paging signals each having an address signal indicating a unique address corresponding to at least one of said plurality of pagers associated therewith;

transmitting repeatedly a same paging signal in each of said plurality of paging signal frames, said step of transmitting repeatedly including steps of;

inserting a new paging signal to be transmitted by said base station for a first time into said first one of said plurality n fixed-length subframes, and

inserting a repeated paging signal to be transmitted by said base station for at least a second time into one of said n fixed-length subframes positioned according to a number of times that said repeated paging signal is to be transmitted currently by said base station, said repeated paging signal being positioned differently for each transmission thereof.

7. A method of communicating repeatedly a paging signal from a base station to at least one of a plurality of pagers according to claim 6, said method further comprising a step of:

removing said repeated paging signal from one of said n fixed-length subframes positioned one less than said number of times that said repeated paging signal is to be transmitted currently by said base station.

8. A method of receiving a paging signal transmitted repeatedly from a base station to a plurality of pagers, said method comprising steps of:

receiving a plurality of paging signal frames from said base station transmitted via at least one radio channel, each of said plurality n of paging signal frames including a plurality n of fixed-length subframes, n being a natural number, a first of said plurality n of fixed-length subframes being closest to a synchronization signal from said base station and an n^th of said plurality n of fixed-length subframes being farthest from said synchronization signal, each of said plurality n of fixed-length subframes containing a plurality of paging signals each having an address signal indicating a unique address corresponding to at least one of said plurality of pagers associated therewith;

receiving repeatedly a same paging signal in each of said plurality of paging signal frames, said step of receiving repeatedly said same paging signal comprising steps of;

receiving a new paging signal transmitted by said base station for a first time in said first one of said plurality n fixed-length subframes, and

receiving a repeated paging signal transmitted by said base station for at least a second time in one of said n fixed-length subframes positioned according to a number of times that said repeated paging signal has been transmitted by said base station, said repeated paging signal being positioned differently for each transmission thereof.

9. A pager in a mobile radio communication system according to claim 8, wherein said step of receiving repeatedly further comprises steps of:

storing said new paging signal;

developing reliability information based on said stored new paging signal; and

performing a bit decision on said repeated paging signal using said developed reliability information.

10. A pager in a mobile radio communication system according to claim 8, wherein said step of receiving repeatedly further comprises steps of:

storing said new paging signal and said repeated paging signal;

developing reliability information based on said stored new paging signal and said repeated paging signal; and

performing a bit decision on said paging signal each time received subsequent to said at least said second time using said developed reliability information.