High-efficiency control of radio burst signal transmission system

• US 20060002459A1
• Filed: 06/28/2005
• Published: 01/05/2006
• Est. Priority Date: 06/30/2004
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Kikuma, Tomohiro
• Granted Patent: US 7,525,916 B2
• Time in Patent Office: Days
• US Class Current: 375/225
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0007 by modifying the frame length
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/1809 Selective-repeat protocols

Abstract

A radio burst signal transmission system operates to switch between a first control process for optimizing the number of bits added per symbol depending on the probability of successful reception of a successful reception indication signal and a second control process for divisionally sending a burst signal, depending on the state of a propagation path between a base station and a terminal. A fragmentation control request determining circuit in each of the base station and the terminal determines an average value and a variance value of time-depending variations of an error of a propagation path function, and a burst signal length of a reception burst signal, from the reception burst signal that is received from the terminal and the base station, and determines a pointer for requesting switching from the first control process to the second control process. When the terminal and the base station receive the request from the base station and the terminal, respectively, a fragmentation control circuit switches from the first control process to the second control process and sends a transmission burst signal to the base station and the terminal if the burst signal length of the reception burst signal exceeds a predetermined value.

Claims

1. An adaptive transmission rate control process for being performed by a base station or a terminal belonging to the base station in a radio burst signal transmission system, said process comprising the steps of:

determining, in a first station, from a reception burst signal received from a second station, an average value and a variance value of time dependent variations of an error of a propagation path function between said first station and said second station, and a burst signal length of said reception burst signal, and determining a pointer to request switching from a first control process for optimizing the number of bits added per symbol depending on the probability of successful reception of a successful reception indication signal to a second control process for divisionaily sending the transmission burst signal, based on the average value, the variance value, and the burst signal length which are thus determined;

if said first station detects an data error of said reception burst signal and detects that said pointer has become larger than a predetermined first value, sending a first request to switch from said first control process to said second control process, from said first station to said second station;

if said first station detects no data error of said reception burst signal and detects that said pointer has become smaller than a predetermined second value, sending a second request to switch from said second control process to said first control process, from said first station to said second station;

if said second station receives said first request from said first station and also detects that the burst signal length of a transmission burst signal has become larger than a predetermined third value, switching from said first control process to said second control process and sending said transmission burst signal from said second station to said first station; and

if said second station receives said second request from said first station, switching from said second control process to said first control process and sending said transmission burst signal from said second station to said first station.

2. The adaptive transmission rate control process according to claim 1, wherein said pointer is produced by dividing the product of the average value of the time dependent variations of the error of the propagation path function between said first station and said second station and the burst signal length of said reception burst signal, by the variance value of the time dependent variations of the error of the propagation path function between said first station and said second station.

3. The adaptive transmission rate control process according to claim 1, wherein said predetermined second value is smaller than said predetermined first value.

4. The adaptive transmission rate control process according to claim 1, wherein said predetermined third value is changed depending on the frequency with which said first request is received.

5. The computer program for executing each of the steps according to claim 1, with a computer serving as the base station, which is either said first station or said second station, or the terminal belonging to said base station.

6. A base station to which a plurality of terminals belong in a radio burst signal transmission system, said base station comprising:

means for determining, from a reception burst signal received from one of said terminals, an average value and a variance value of time dependent variations of an error of a propagation path function between said base station and said terminal, and a burst signal length of said reception burst signal, and determining a pointer to request switching from a first control process for optimizing the number of bits added per symbol depending on the probability of successful reception of a successful reception indication signal to a second control process for divisionally sending the transmission burst signal, based on the average value, the variance value, and the burst signal length which are thus determined;

means for, if said base station detects an data error of said reception burst signal and detects that said pointer has become larger than a predetermined first value, sending a first request to switch from said first control process to said second control process, to said terminal;

means for, if said base station detects no data error of said reception burst signal and detects when said pointer becomes smaller than a predetermined second value, sending a second request for switching from said second control process to said first control process, to said terminal;

means for, if said base station receives a request corresponding to said first request made by said terminal from said terminal and also detects that the burst signal length of a transmission burst signal has become larger than a predetermined third value, switching from said first control process to said second control process and sending said transmission burst signal to said terminal; and

means for, if said base station receives a request corresponding to said second request made by said terminal from said terminal, switching from said second control process to said first control process and sending said transmission burst signal to said terminal.

7. A terminal belonging to a base station in a radio burst signal transmission system, said terminal comprising:

means for determining, from a reception burst signal received from said base station, an average value and a variance value of time dependent variations of an error of a propagation path function between said base station and said terminal, and a burst signal length of said reception burst signal, and determining a pointer to request switch from a first control process for optimizing the number of bits added per symbol depending on the probability of successful reception of a successful reception indication signal to a second control process for divisionally sending the transmission burst signal, based on the average value, the variance value, and the burst signal length which are thus determined;

means for, if said terminal detects an data error of said reception burst signal and detects that said pointer has become larger than a predetermined first value, sending a first request to switch from said first control process to said second control process, to said base station;

means for, if said terminal detects no data error of said reception burst signal and detects that said pointer has become smaller than a predetermined second value, sending a second request to switch from said second control process to said first control process, to said base station;

means for, if said terminal receives a request corresponding to said first request made by said base station from said base station and also detects that the burst signal length of a transmission burst signal has become larger than a predetermined third value, switching from said first control process to said second control process and sending said transmission burst signal to said base station; and

means for, if said terminal receives a request corresponding to said second request made by said base station from said base station, switching from said second control process to said first control process and sending said transmission burst signal to said base station.

8. A radio burst signal transmission system, comprising:

means for determining, from a reception burst signal received from one of said terminals, an average value and a variance value of time dependent variations of an error of a propagation path function between said base station and said terminal, and a burst signal length of said reception burst signal, and determining a pointer to request switching from a first control process for optimizing the number of bits added per symbol depending on the probability of successful reception of a successful reception indication signal to a second control process for divisional sending the transmission burst signal, based on the average value, the variance value, and the burst signal length which are thus determined;

means for, if said base station detects an data error of said reception burst signal and detects that said pointer has become larger than a predetermined first value, sending a first request to switch from said first control process to said second control process, to said terminal;

means for, if said base station detects no data error of said reception burst signal and detects when said pointer becomes smaller than a predetermined second value, sending a second request for switching from said second control process to said first control process, to said terminal;

means for, if said base station receives a request corresponding to said first request made by said terminal from said terminal and also detects that the burst signal length of a transmission burst signal has become larger than a predetermined third value, switching from said first control process to said second control process and sending said transmission burst signal to said terminal;

means for, if said base station receives a request corresponding to said second request made by said terminal from said terminal, switching from said second control process to said first control process and sending said transmission burst signal to said terminal;

means for determining, from a reception burst signal received from said base station, an average value and a variance value of time dependent variations of an error of a propagation path function between said base station and said terminal, and a burst signal length of said reception burst signal, and determining a pointer to request switch from a first control process for optimizing the number of bits added per symbol depending on the probability of successful reception of a successful reception indication signal to a second control process for divisional sending the transmission burst signal, based on the average value, the variance value, and the burst signal length which are thus determined;

means for, if said terminal detects an data error of said reception burst signal and detects that said pointer has become larger than a predetermined first value, sending a first request to switch from said first control process to said second control process, to said base station;

means for, if said terminal detects no data error of said reception burst signal and detects that said pointer has become smaller than a predetermined second value, sending a second request to switch from said second control process to said first control process, to said base station;

means for, if said terminal receives a request corresponding to said first request made by said base station from said base station and also detects that the burst signal length of a transmission burst signal has become larger than a predetermined third value, switching from said first control process to said second control process and sending said transmission burst signal to said base station;

means for, if said terminal receives a request corresponding to said second request made by said base station from said base station, switching from said second control process to said first control process and sending said transmission burst signal to said base station; and

means for switching between a first control process for optimizing the number of bits added per symbol depending on the probability of successful reception of a successful reception indication signal and a second control process for divisionally sending a burst signal, depending on the state of a propagation path between said base station and terminals.