Systems, devices and methods for communicating data with unmanned aerial vehicles using underlay broadcast channel
An unmanned aerial vehicle (UAV) and base station are disclosed that communicate within a first cell via schedule requests to set up transmission of up-link data. The UAV additionally communicates up-link data via a grant-free underlay broadcast channel to one or more neighboring base stations of the terrestrial cellular network. Transmitters, receivers, related methods are also disclosed for modulation and demodulation of the transmission packets.
1. An unmanned aerial vehicle including a processor and at least one transmitter configured to:
communicate a scheduling request to a first base station within a first cell; and
communicate its uplink (UL) transmission information over an underlay broadcast channel with at least one neighboring base station within another cell, wherein the underlay broadcast channel has a power level below a noise level for a communication spectrum;
wherein the UL transmission information is communicated to the at least one neighboring base station after communicating the scheduling request and prior to any communication of UL data from the at least one transmitter to the first base station.
2. The unmanned aerial vehicle of claim 1 , wherein processor and the at least one transmitter are further configured to generate the UL transmission information as spread spectrum signals.
3. The unmanned aerial vehicle of claim 2 , wherein the UL transmission information includes spectral resources to be used by the unmanned aerial vehicle when communicating with the first base station.
4. The unmanned aerial vehicle of claim 3 , wherein the spectral resources include a band of transmission for communication with the first base station.
5. The unmanned aerial vehicle of claim 3 , wherein the spectral resources include a signal power level for data packets during transmission when communicating with the first base station.
6. The unmanned aerial vehicle of claim 3 , wherein the spectral resources include a duration of time for data packets during transmission when communicating with the first base station.
7. The unmanned aerial vehicle of claim 2 , wherein the spread spectrum signals are direct sequence spread spectrum (DSSS) packets.
8. The unmanned aerial vehicle of claim 7 , wherein the DSSS packets are cycle prefix DSSS (CP-DSSS) packets.
9. The unmanned aerial vehicle of claim 7 , wherein each packet is spread across a single OFDM symbol frame.
10. The unmanned aerial vehicle of claim 7 , wherein each packet is spread across a plurality of OFDM symbol frames.
11. The unmanned aerial vehicle of claim 7 , wherein each packet of the DSSS packets includes at least one reference bit and information bits.
12. The unmanned aerial vehicle of claim 11 , wherein the at least one reference bit is present in a single OFDM symbol frame.
13. The unmanned aerial vehicle of claim 12 , wherein the at least one reference bit includes multiple reference bits present across multiple OFDM symbol frames.
14. The unmanned aerial vehicle of claim 7 , wherein a packet of the DSSS packets includes a single reference bit for the packet and other packets of the DSSS packets, wherein the other packets include multiple information bits without their own reference bit.
15. The unmanned aerial vehicle of claim 1 , wherein the UL transmission information is transmitted as grant-free broadcasts of information with the at least one neighboring base station.
16. A communication system, comprising:
a number of base stations; and
an unmanned aerial vehicle configured to:
communicate a scheduling request with a first base station of the number of base stations within a first cell; and
communicate associated uplink (UL) transmission information over an underlay broadcast channel with at least a second base station of the number of base stations within another cell, wherein the underlay broadcast channel has a power level below a noise level for a communication spectrum;
wherein the UL transmission information is communicated to the at least the second base station after communicating the scheduling request and prior to any communication of UL data from the unmanned aerial vehicle to the first base station.
17. The communication system of claim 16 , wherein the UL transmission information includes spread spectrum signals.
18. The communication system of claim 16 , wherein the UL transmission information includes spectral resources to be used by the unmanned aerial vehicle when communicating with the first base station.
19. A method of operating a communication system, comprising:
communicating, from an unmanned aerial vehicle, a scheduling request to a first base station within a first cell; and
communicating, from the unmanned aerial vehicle, associated uplink (UL) transmission information over an underlay broadcast channel to at least a second base station within another cell, wherein the underlay broadcast channel has a power level below a noise level for a communication spectrum, wherein the UL transmission information is communicated to the at least the second base station after communicating the scheduling request and prior to any communication of UL data from the unmanned aerial vehicle to the first base station.
20. The method of claim 19 , wherein communicating UL transmission information comprises communicating grant-free broadcasts of information with the at least the second base station.