Adaptive transmission power control for cognitive radio
Embodiments of cognitive radio technology can recover and utilize under-utilized portions of statically-allocated radio-frequency spectrum. A plurality of sensing methods can be employed. Transmission power control can be responsive to adjacent channel measurements. Digital pre-distortion techniques can enhance performance. Embodiments of a high DNR transceiver architecture can be employed.
1. A cognitive radio system comprising:
a cognitive radio receiver adapted to
receive a broadcast signal, and,
provide a first specified channel and a plurality of adjacent channels, responsive to the broadcast signal,
wherein the plurality of adjacent channels comprises a first adjacent channel and a second adjacent channel;
a power measurement and control unit adapted to
receive the first specified channel and the plurality of adjacent channels,
determine a first parameter,
determine a second parameter,
determine a third parameter,
wherein the first parameter corresponds to a first adjacent channel received signal power,
wherein the second parameter corresponds to a second adjacent channel received signal power,
wherein the third parameter corresponds to an adjacent channel leakage ratio; and,
a control element adapted to
receive the first parameter, the second parameter, the third parameter, a fourth parameter, and a fifth parameter,
determine a value corresponding to a maximum allowed cognitive user transmission power level for the first specified channel, responsive to the received parameters, and,
provide a control signal corresponding to the first specified channel,
wherein the control signal specifies the value,
wherein the fourth parameter corresponds to a specified signal power loss, and,
wherein the fifth parameter corresponds to a specified desired-to-undesired ratio.
2. The system of claim 1 wherein:
the value is at least partially determined by a combination of:
the lesser of the first parameter and the second parameter,
the third parameter,
the fourth parameter, and,
the fifth parameter.
3. The system of claim 1 wherein:
one or more of the first, second, and third parameters are at least partially determined by a collective sensing technique.
4. A method of adaptive transmission power control for cognitive radio comprising the steps of:
receiving a broadcast signal;
providing a first specified channel and a plurality of adjacent channels, responsive to the broadcast signal;
receiving the first specified channel and the plurality of adjacent channels;
determining a first parameter;
determining a second parameter;
determining a third parameter;
receiving the first parameter, the second parameter, the third parameter, a fourth parameter, and a fifth parameter;
determining a value corresponding to a maximum allowed cognitive user transmission power level for the first specified channel, responsive to the received parameters; and,
providing a control signal corresponding to the first specified channel;
wherein the control signal specifies the value;
wherein the plurality of adjacent channels comprises a first adjacent channel and a second adjacent channel;
wherein the first parameter corresponds to a first adjacent channel received signal power;
wherein the second parameter corresponds to a second adjacent channel received signal power;
wherein the third parameter corresponds to an adjacent channel leakage ratio;
wherein the fourth parameter corresponds to a specified signal power loss; and,
wherein the fifth parameter corresponds to a specified desired-to-undesired ratio.
5. The method of claim 4 further comprising the step of:
at least partially determining the value by a combination of:
the lesser of the first parameter and the second parameter,
the third parameter,
the fourth parameter, and,
the fifth parameter.
6. The method of claim 4 further comprising the step of:
at least partially determining one or more of the first, second, and third parameters by a collective sensing technique.