Air-to-ground co-channel interference avoidance system
View Patent ↗Techniques to reduce scheduling grants to minimize or eliminate the use of control channels, at the expense of flexibility, allow protection of the system from unnecessary retransmissions in case of interference from the primary system. Use of a single grant to allocate a set of resources across all carriers, or communication channels simplifies the system at the cost of retransmission of a grant for all carriers in the case if interference corrupts the transmission of a subset of the carriers. Thus, complementing a single grant embodiment with detection of the affected frequency carriers or victim carriers and remove such carriers from the carrier aggregation configuration allows more efficient use of the allocated spectrum.
1. A wireless communication system comprising:
a transceiver unit disposed within a ground station included in the wireless communication system, the transceiver unit utilized by the wireless communication system to communicate on a plurality of carriers, each carrier of the plurality of carriers being a different, respective communication channel corresponding to a different, respective frequency of a frequency spectrum utilized by the plurality of carriers, the wireless communication system utilizing the frequency spectrum to provide wireless communications, wherein the plurality of carriers is configured by the wireless communication system via grants communicated over a control channel; and
a computer processor coupled to the transceiver unit and configured to:
cause the transceiver unit to communicate, over the control channel, a first transmission grant indicating two or more of the plurality of carriers allocated to the transceiver unit to utilize for sending transmissions;
cause the transceiver unit to transmit, in accordance with the first transmission grant communicated by the transceiver unit, data on the indicated two or more of the plurality of carriers;
configure the transceiver unit to detect a threshold level of interference on a particular carrier of the two or more of the plurality of carriers; and
in response to detecting the threshold level of interference:
cause the transceiver unit to communicate, over the control channel, a retransmission grant excluding an indication of the particular carrier and including an indication of the other carriers of the two or more of the plurality of carriers indicated by the first transmission grant, and
cause the transceiver unit to retransmit, to the receiving unit, with the retransmission grant communicated by the transceiver unit, the data on the two or more of the plurality of carriers.
2. The wireless communication system of claim 1 , wherein:
the wireless communication system is a secondary user of the frequency spectrum utilized by the plurality of carriers, and
the transceiver unit is configured to operate in accordance with the one or more restrictions to which the secondary user is subjected on at least one of the plurality of carriers.
3. The wireless communication system of claim 2 , wherein the wireless communication system is an air-to-ground communication system.
4. The wireless communication system of claim 2 , wherein the one or more restrictions with which the transceiver unit operates in accordance is relate to a digital modulation service associated with the wireless communications.
5. The wireless communication system of claim 2 , wherein the transceiver unit is configured to allow a primary user to transmit and receive on at least one of the plurality of carriers co-presently with the transceiver unit transmitting on the at least one of the plurality of carriers.
6. The wireless communication system of claim 5 , wherein the primary user comprises a satellite communication system.
7. The wireless communication system of claim 1 , wherein to detect the threshold level of interference, the transceiver unit is configured to measure a block error ratio (BLER) associated with the particular carrier.
8. The wireless communication system of claim 1 , wherein to detect the threshold level of interference, the transceiver unit is configured to monitor the particular carrier during a guard time of a time division duplex (TDD) communication protocol to detect a presence of at least one signal transmitted by a primary user.
9. The air-to-ground communication system of claim 1 , wherein to detect the threshold level of interference, the transceiver unit is configured to detect an absence of an acknowledgement on the particular carrier.
10. A method, performed by a computer processor comprising:
configuring a transceiver unit to be utilized by a wireless communication system to communicate on a plurality of carriers, the transceiver unit disposed within a ground station included in the wireless communications system, each carrier of the plurality of carriers being a different, respective communication channel corresponding to a different, respective frequency of a frequency spectrum utilized by the plurality of carriers, and the wireless communication system utilizing the frequency spectrum to provide wireless communications, wherein the plurality of carriers is configured by the wireless communication system using grants communicated over a control channel, and wherein at least one of the communication services comprises a guard time where the transceiver unit halts transmission;
causing the transceiver unit to communicate, over the control channel, a first transmission grant indicating two or more of the plurality of carriers allocated to the transceiver unit to utilize for sending transmissions;
causing the transceiver unit to transmit, in accordance with the first transmission grant communicated by the transceiver unit, data on the indicated two or more of the plurality of carriers;
configuring the transceiver unit to detect a threshold level of interference on a particular carrier of the two or more of the plurality of carriers; and
in response to detecting the threshold level of interference:
causing the transceiver unit to communicate, over the control channel, a retransmission grant excluding an indication of the particular carrier and including an indication of the other carriers of the two or more of the plurality of carriers indicated by the first transmission grant, and
causing the transceiver unit to retransmit, to the receiving unit, in accordance with the retransmission grant communicated by the transceiver unit, the data on the two or more of the plurality of carriers.
11. The method of claim 10 , wherein the wireless communication system is a secondary user of the frequency spectrum utilized by the plurality of carriers, the method further comprising:
causing the transceiver unit to operate in accordance with the one or more restrictions to which the secondary user is subjected on at least one of the plurality of carriers.
12. The method of claim 11 , wherein the wireless communication system is an air-to-ground communication system.
13. The method of claim 11 , wherein the one or more restrictions with which the transceiver unit operates in accordance is relate to a digital modulation service associated with the wireless communications.
14. The method of claim 11 , further comprising:
causing the transceiver unit to allow a primary user to transmit and receive on at least one of the air-to-ground communication channels.
15. The method of claim 14 , wherein the primary user comprises a satellite communication system.
16. The method of claim 10 , wherein configuring the transceiver unit to detect a threshold level of interference comprises:
causing the transceiver unit to measure a block error ratio (BLER) associated with the particular carrier.
17. The method of claim 10 , wherein configuring the transceiver unit to detect a threshold level of interference comprises:
configuring the transceiver unit to detect a threshold level of interference during the guard time.
18. The method of claim 10 , wherein configuring the transceiver unit to detect a threshold level of interference comprises:
configuring the transceiver to detect an absence of an acknowledgement on the particular channel corresponding.