Method and apparatus for inter-frame sharing in cognitive radio system

• US 20100118808A1
• Filed: 11/06/2009
• Published: 05/13/2010
• Est. Priority Date: 11/07/2008
• Status: Abandoned Application

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Lee, Geun-Ho, Lim, Eun-Taek, Shan, Cheng, Kim, Sang-Bum, Woo, Jung-Soo, Kim, Ho-Dong, Park, Yong-Ho
• Application Number:
  US12/590,430
• Publication Number:
  US 20100118808A1
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks

Abstract

An operating method of a source Base Station (BS) for inter-frame sharing in a Cognitive Radio (CR) system includes generating a first random number for a frame contention; requesting the frame contention to one or more destination BSs by carrying the first random number; receiving responses for the frame contention request from the one or more destination BSs; and when positive responses for the frame contention request are received from all of the one or more destination BSs, occupying one or more requested contention frames.

Claims

1. An operating method of a source Base Station (BS) for inter-frame sharing in a Cognitive Radio (CR) system, the method comprising:

generating a first random number for a frame contention;

requesting the frame contention to one or more destination BSs corresponding to the first random number;

receiving responses for the frame contention request from the one or more destination BSs; and

occupying one or more requested contention frames, when positive responses for the frame contention request are received from all of the one or more destination BSs.

2. The operating method of claim 1, further comprising:

sending Acknowledgement (ACK) for the positive responses to the one or more destination BSs.

3. The operating method of claim 1, further comprising, when one or more negative responses are received for the frame request from the one or more destination BSs:

generating a second random number for a next frame contention;

requesting the frame contention to the one or more destination BSs together the second random number;

receiving responses of the frame contention request from the one or more destination BSs; and

occupying one or more requested contention frames when positive responses are received for the frame contention request from all of the one or more destination BSs,

wherein ACK for the positive response is transmitted to the one or more destination BSs.

4. The operating method of claim 3, further comprising:

sending Negative ACK (NACK) for the negative response to the one or more destination BSs.

5. The operating method of claim 1, wherein the first random number and the second random number are determined by a predefined Probability Density Function (PDF), and

the predefined PDF is either a first equation or a second equation, the first equation defined as:

$P_{N_0}<br><br>\left(n\right)=\{\begin{array}{cc}\frac{1}{X-X^{\mathrm{\prime <br><br>}}},& X^{\mathrm{\prime <br><br>}}-1\le <br><br>n\le <br><br>X-1\\ 0,& \mathrm{otherwise}\end{array}$

where X and X′

denote the number of bits for representing a random number n, and X and X′

are roots that satisfy 0≦

X′

≦

X and

${\left(\frac{X^{\mathrm{\prime <br><br>}}}{X}\right)}^{L+1}-P_0<br><br>\left(L-1\right)<br><br>\left(\frac{X^{\mathrm{\prime <br><br>}}}{X}\right)+\left(P_0<br><br>L-P_0-1\right)=0,$

and wherein the second equation is defined as;

$P_{N_0}<br><br>\left(n\right)=,\{\begin{array}{cc}1,& n=\left[X·<br><br>\sqrt[L]{P_0}\right]\\ 0,& \mathrm{otherwise}\end{array}$

where X denotes the number of bits for representing the random number n, P₀ denotes a probability that the source BS wins in the frame contention, and L denotes the number of BSs taking part in the frame contention.

6. The operating method of claim 1, wherein the frame contention request targets every frame in a superframe, or one or more selected frames in a superframe.

7. The operating method of claim 1, wherein, before the frame contention request, when there exist one or more frames unoccupied, the one or more unoccupied frames are occupied.

8. An operating method of a source Base Station (BS) for inter-frame sharing in a Cognitive Radio (CR) system, the method comprising:

generating a first random number for a frame contention;

requesting the frame contention to a corresponding destination BS with the first random number;

receiving a response for the frame contention request from the corresponding destination BS, and requesting the frame contention to a next corresponding destination BS together the first random number or a newly generated second random number; and

receiving a response for the frame contention request from the next corresponding destination BS.

9. The operating method of claim 8, wherein, when positive responses are received for the frame request from all of the corresponding destination BSs, a corresponding contention frame is occupied and Acknowledgement (ACK) is transmitted to the corresponding destination BSs.

10. The operating method of claim 8, further comprising, when one or more negative responses are received for the frame request from the corresponding destination BSs:

generating a third random number for a next frame contention;

requesting the frame contention to the corresponding destination BS together the third random number;

receiving a response of the frame contention request from the corresponding destination BS, and requesting the frame contention to a next corresponding destination BS by carrying the third random number or a newly generated random number; and

receiving a response for the frame contention request from the next corresponding destination BS.

11. The operating method of claim 8, wherein the generated random numbers are determined by a predefined Probability Density Function (PDF), and

the predefined PDF one of a first equation and a second equation, the first equation defined as:

$P_{N_0}<br><br>\left(n\right)=\{\begin{array}{cc}\frac{1}{X-X^{\mathrm{\prime <br><br>}}},& X^{\mathrm{\prime <br><br>}}-1\le <br><br>n\le <br><br>X-1\\ 0,& \mathrm{otherwise}\end{array}$

where X and X′

denote the number of bits for representing a random number n, and X and X′

are roots which satisfy 0≦

X′

≦

X and

${\left(\frac{X^{\mathrm{\prime <br><br>}}}{X}\right)}^{L+1}-P_0<br><br>\left(L-1\right)<br><br>\left(\frac{X^{\mathrm{\prime <br><br>}}}{X}\right)+\left(P_0<br><br>L-P_0-1\right)=0,$

and the second equation is defined as;

$P_{N_0}<br><br>\left(n\right)=,\{\begin{array}{cc}1,& n=\left[X·<br><br>\sqrt[L]{P_0}\right]\\ 0,& \mathrm{otherwise}\end{array}$

where X denotes the number of bits for representing the random number n, P₀ denotes a probability that the source BS wins in the frame contention, and L denotes the number of BSs taking part in the frame contention.

12. The operating method of claim 8, wherein the frame contention request targets every frame in a superframe, or one or more selected frames in a superframe.

13. An operating method of a destination Base Station (BS) for inter-frame sharing in a Cognitive Radio (CR) system, the method comprising:

receiving a frame contention request together a first random number from a source BS;

comparing the first random number and a second random number; and

responding to the frame request from the source BS according to a comparison result.

14. The operating method of claim 13, further comprising:

generating the second random number.

15. The operating method of claim 13, further comprising:

releasing the requested contention frame when the first random number is greater than the second random number, and keeping occupying the requested contention frame when the first random number is less than or equal to the second random number.

16. The operating method of claim 13, wherein a positive response is transmitted to the source BS when the first random number is greater than the second random number, and a negative response is transmitted when the first random number is less than or equal to the second random number.

17. An apparatus of a source Base Station (BS) for inter-frame sharing in a Cognitive Radio (CR) system, the apparatus comprising:

a random number generator configured to generate a first random number for a frame contention;

a controller configured to request the frame contention to one or more destination BSs by carrying the first random number, and receive responses for the frame contention request from the one or more destination BSs; and

a frame resource arranger configured to, when positive responses are received for the frame contention request from all of the one or more destination BSs, occupy one or more requested contention frames.

18. The apparatus of claim 17, wherein the controller is configured to send Acknowledgement (ACK) for the positive responses to the one or more destination BSs.

19. The apparatus of claim 17, wherein, when one or more negative responses are received for the frame request from the one or more destination BSs,

the random number generator is configured to generate a second random number for a next frame contention,

the controller is configured to request the frame contention to the one or more destination BSs by carrying the second random number, and receive responses of the frame contention request from the one or more destination BSs,

when positive responses are received for the frame contention request from all of the one or more destination BSs, the frame resource arranger is configured to occupy one or more requested contention frames, and

the controller is configured to send ACK for the positive response to the one or more destination BSs.

20. The apparatus of claim 19, wherein the controller is configured to send Negative ACK (NACK) for the negative response to the one or more destination BSs.

21. The apparatus of claim 17, wherein the first random number and the second random number are determined by a predefined Probability Density Function (PDF), and

the predefined PDF is one of a first equation and a second equation, the first equation defined as:

$P_{N_0}<br><br>\left(n\right)=\{\begin{array}{cc}\frac{1}{X-X^{\mathrm{\prime <br><br>}}},& X^{\mathrm{\prime <br><br>}}-1\le <br><br>n\le <br><br>X-1\\ 0,& \mathrm{otherwise}\end{array}$

where X and X′

denote the number of bits for representing a random number n, and X and X′

are roots which satisfy 0≦

X′

≦

X and

${\left(\frac{X^{\mathrm{\prime <br><br>}}}{X}\right)}^{L+1}-P_0<br><br>\left(L-1\right)<br><br>\left(\frac{X^{\mathrm{\prime <br><br>}}}{X}\right)+\left(P_0<br><br>L-P_0-1\right)=0,$

and the second equation is defined as;

$P_{N_0}<br><br>\left(n\right)=,\{\begin{array}{cc}1,& n=\left[X·<br><br>\sqrt[L]{P_0}\right]\\ 0,& \mathrm{otherwise}\end{array}$

where X denotes the number of bits for representing the random number n, P₀ denotes a probability that the source BS wins in the frame contention, and L denotes the number of BSs taking part in the frame contention.

22. The apparatus of claim 17, wherein the frame contention request targets every frame in a superframe, or one or more selected frames in a superframe.

23. The apparatus of claim 17, wherein, before the frame contention request, when there exists one or more frames unoccupied, the one or more unoccupied frames are occupied.

24. An apparatus of a source Base Station (BS) for inter-frame sharing in a Cognitive Radio (CR) system, the apparatus comprising:

a random number generator configured to generate a first random number for a frame contention; and

a controller configured to request the frame contention to a corresponding destination BS by carrying the first random number, receive a response for the frame contention request from the corresponding destination BS, request the frame contention to a next corresponding destination BS by carrying the first random number or a newly generated second random number, and receive a response for the frame contention request from the next corresponding destination BS.

25. The apparatus of claim 24, further comprising:

a frame resource arranger configured to, when positive responses are received for the frame request from all of the corresponding destination BSs, occupy a corresponding contention frame.

26. The apparatus of claim 24, wherein, when one or more negative responses are received for the frame request from the corresponding destination BSs,

the random number generator is configured to generate a third random number for a next frame contention,

the controller is configured request the frame contention to a corresponding destination BS by carrying the third random number, receive a response of the frame contention request from the corresponding destination BS, request the frame contention to a next corresponding destination BS by carrying the third random number or a newly generated random number, and receive a response for the frame contention request from the next corresponding destination BS.

27. The apparatus of claim 24, wherein the generated random numbers are determined by a predefined Probability Density Function (PDF), and

the predefined PDF is one of a first equation and a second equation, the first equation defined as:

$P_{N_0}<br><br>\left(n\right)=\{\begin{array}{cc}\frac{1}{X-X^{\mathrm{\prime <br><br>}}},& X^{\mathrm{\prime <br><br>}}-1\le <br><br>n\le <br><br>X-1\\ 0,& \mathrm{otherwise}\end{array}$

where X and X′

denote the number of bits for representing a random number n, and X and X′

are roots which satisfy 0≦

X′

≦

X and

${\left(\frac{X^{\mathrm{\prime <br><br>}}}{X}\right)}^{L+1}-P_0<br><br>\left(L-1\right)<br><br>\left(\frac{X^{\mathrm{\prime <br><br>}}}{X}\right)+\left(P_0<br><br>L-P_0-1\right)=0,$

and the second equation is defined as;

$P_{N_0}<br><br>\left(n\right)=,\{\begin{array}{cc}1,& n=\left[X·<br><br>\sqrt[L]{P_0}\right]\\ 0,& \mathrm{otherwise}\end{array}$

where X denotes the number of bits for representing the random number n, P₀ denotes a probability that the source BS wins in the frame contention, and L denotes the number of BSs taking part in the frame contention.

28. The apparatus of claim 24, wherein the frame contention request targets every frame in a superframe, or one or more selected frames in a superframe.

29. An apparatus of a destination Base Station (BS) for inter-frame sharing in a Cognitive Radio (CR) system, the apparatus comprising:

a controller configured to receive a frame contention request comprising a first random number from a source BS; and

a frame resource arranger configured to compare the first random number and a second random number,

wherein the controller is configured to respond to the frame request from the source BS according to a comparison result.

30. The apparatus of claim 29, further comprising:

a random number generator configured to generate the second random number.

31. The apparatus of claim 29, wherein the frame resource arranger is configured to release the requested contention frame when the first random number is greater than the second random number, and keeps occupying the requested contention frame when the first random number is less than or equal to the second random number.

32. The apparatus of claim 29, wherein the controller is configured to send a positive response to the source BS when the first random number is greater than the second random number, and send a negative response when the first random number is less than or equal to the second random number.