Wideband operation in TVWS bands
Disclosed are white space communications systems for wideband communications over TVWS bands. The white space communications systems include tunable frequency filters for providing non-contiguous coverage according to WSDB requirements blocking segments associated with occupied TV channels.
1. A white space communications system for wideband communications over a Television White Space (TVWS) spectrum within a target TVWS band, the system comprising: at least one tunable frequency filter along at least a transmit path for rejecting frequencies within at least one blocked segment of frequencies within a range of frequencies spanned by the target TVWS band; a plurality of RF chains each for communicating over a frequency subportion of the target TVWS band, the frequency subportions of the plurality of RF chains collectively spanning the target TVWS band; and at least one sharp bandpass filter along at least a transmit path for providing sharp rejection of out-of-band emissions (OOBE) outside the range of frequencies spanned by the target TVWS band.
2. The white space communications system of claim 1 , wherein the at least one tunable frequency filter comprises at least one tunable bandpass filter.
3. The white space communications system of claim 2 , wherein the at least one tunable bandpass filter comprises one or more tunable bandpass filters located along each RF chain.
4. The white space communications system of claim 3 , wherein the RF chains are multiplexed by multiplexers and demultiplexed by demultiplexers separate from the multiplexers.
5. The white space communications system of claim 4 , wherein the at least one sharp bandpass filter comprises a plurality of bandpass filters collectively spanning the target TVWS band, each bandpass filter located in a respective RF chain in a transmit path.
6. The white space communications system of claim 3 , wherein the at least one tunable frequency filter comprises at least one tunable band-stop filter, and wherein the at least one sharp bandpass filter comprises a plurality of bandpass filters collectively spanning the target TVWS band, each bandpass filter located in a respective RF chain in a transmit path.
7. The white space communications system of claim 3 , wherein the at least one tunable frequency filter comprises at least one tunable band-stop filter, and wherein the at least one sharp bandpass filter comprises a sharp wideband bandpass filter.
8. The white space communications system of claim 2 , wherein the at least one tunable frequency filter comprises at least one tunable band-stop filter having a band-stop bandwidth at least as wide as the bandwidth of a single television channel.
9. The white space communications system of claim 2 , wherein the at least one sharp bandpass filter comprises a plurality of bandpass filters collectively spanning the target TVWS band.
10. The white space communications system of claim 2 , wherein the at least one sharp bandpass filter comprises a sharp wideband bandpass filter.
11. The white space communications system of claim 1 , wherein the at least one tunable frequency filter comprises at least one tunable band-stop filter having a band-stop bandwidth at least as wide as the bandwidth of a single television channel.
12. The white space communications system of claim 11 , wherein each at least one tunable band-stop filter has a tunable center frequency and has a fixed bandwidth substantially the same as that of a TV channel.
13. The white space communications system of claim 11 , wherein each at least one tunable band-stop filter has a tunable center frequency and a tunable bandwidth.
14. The white space communications system of claim 11 , wherein the at least one sharp bandpass filter comprises a plurality of bandpass filters collectively spanning the target TVWS band.
15. The white space communications system of claim 11 , wherein the at least one sharp bandpass filter comprises a sharp wideband bandpass filter.
16. The white space communications system of claim 15 , wherein the RF chains are multiplexed by multiplexers and demultiplexed by demultiplexers separate from the multiplexers.
17. The white space communications system of claim 14 , wherein the RF chains are multiplexed by multiplexers and demultiplexed by demultiplexers separate from the multiplexers.
18. The white space communications system of claim 1 , wherein the at least one sharp bandpass filter comprises a sharp wideband bandpass filter.
19. The whitespace communications system of claim 1 , wherein the at least one sharp bandpass filter comprises a plurality of bandpass filters collectively spanning the target TVWS band, each bandpass filter located along a respective RF chain.