Spectrum sharing in a wireless communication network
A system and method for synchronous spectrum sharing for use in a wireless communication system based on orthogonal frequency-division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) signaling is disclosed. The system includes a frame detector configured to detect a frame of a broadcast waveform and extract sub-carrier information from the frame. Sub-carrier information may include information on usable sub-carrier and pilot sub-carriers for secondary users. The system allows transmitting data from the secondary user node in unused sub-carriers thereby making efficient use of unused or idle spectrum. Accordingly, secondary users of wireless communication systems can dynamically form ad-hoc mesh network communications in fixed or mobile scenarios.
1. A spectrum sharing system for use in a wireless communication system having a primary user node and a secondary user node, the system comprising:
a frame detector in the secondary user node configured to detect a frame of a broadcast waveform and to extract subframe information including idle blocks in the frame, wherein the frame comprises transmitted data; and
a controller configured to identify sub-carriers for the frame usable by the secondary user node from the subframe information,
wherein the secondary user node transmits data in a first one of usable sub-carriers identified in the subframe information.
2. The system set forth in claim 1 , wherein the frame detector is one of:
an OFDM frame detector and an OFDMA frame detector.
3. The system set forth in claim 1 , wherein the broadcast waveform is one of: an OFDM waveform and an OFDMA waveform.
4. The system set forth in claim 1 , wherein the secondary user node comprises a node modem.
5. The system set forth in claim 4 , wherein the node modem is a MANET node modem.
6. The system set forth in claim 4 , wherein the node modem and the frame detector are synchronized.
7. The system set forth in claim 1 , wherein the secondary user node extracts usable pilot sub-carriers for the frame.
8. The system set forth in claim 1 , wherein a second secondary user node transmits data in a second usable sub-carrier identified in the subframe information.
9. The system set forth in claim 1 , wherein the wireless communication system is a WiMAX communication system.
10. For use in a wireless communication network having a primary user node and a secondary user node, a method of spectrum sharing, the method comprising:
detecting a frame of a broadcast waveform in the secondary node;
extracting subframe information including idle blocks in the frame, wherein the frame comprises transmitted data;
identifying sub-carriers for the frame usable by the secondary user node from the subframe information; and
transmitting data from the secondary user node in a first sub-carrier identified in the subframe information.
11. The method set forth in claim 10 , wherein the detecting the frame is accomplished by one of: an OFDM frame detector and an OFDMA frame detector.
12. The method set forth in claim 10 , wherein the broadcast waveform is one of: an OFDM waveform and an OFDMA waveform.
13. The method set forth in claim 10 , wherein the secondary user node comprises a node modem.
14. The method set forth in claim 13 , wherein the node modem is a MANET node modem.
15. The method set forth in claim 13 , further comprising:
synchronizing the node modem and the frame detector.
16. The method set forth in claim 10 , further comprising:
extracting usable pilot sub-carriers for the frame.
17. The method set forth in claim 10 , further comprising:
transmitting data from a second secondary user node into a second sub-carrier identified in the subframe information.
18. The method set forth in claim 10 , further comprising:
dynamically forming an ad hoc mesh network with the secondary user node.
19. The method set forth in claim 10 , wherein the wireless communication network is a WiMAX communication network.
20. For use in a wireless communication system, an apparatus for forming an ad hoc mesh network, the apparatus comprising:
a secondary user node having a node modem; and
a frame detector in the secondary user node configured to detect a frame of a broadcast waveform and extract subframe information including idle blocks in the frame wherein the frame comprises transmitted data,
wherein the secondary user node transmits data in a first unused sub-carrier identified in the subframe information.
21. The apparatus set forth in claim 20 , wherein the node modem and the frame detector are synchronized.
22. The apparatus set forth in claim 20 , wherein the secondary user node extracts usable pilot sub-carriers for the frame.
23. The apparatus set forth in claim 20 , wherein wireless communication system is a WiMAX communication system.