Multiple antenna interference rejection in ultra-wideband real time locating systems

1. An ultra-wideband (UWB) receiver comprising:

a first antenna configured to receive a first signal, the first signal comprising a UWB signal and a first component of an interference signal;

a second antenna configured to receive a second signal, the second signal comprising at least a second component of the interference signal; and

a combiner configured to:

receive the first signal from the first antenna;

receive the second signal from the second antenna; and

combine the first signal and the second signal to generate an output signal providing cancellation of at least part of the first component of the inference signal based at least in part on the second component of the interference signal;

a detector configured to:

receive the output signal of the combiner; and

indicate an interference level associated with the output signal;

a controller configured to:

monitor the interference level associated with the output signal; and

adjust at least one of a variable attenuator and a variable phase shifter in an instance in which the monitored interference level is above a threshold level,

the variable attenuator and the variable phase shifter configured to:

modify the second signal received from the second antenna; and

provide the modified second signal to the combiner;

the controller further configured to:

determine a first ratio of a signal strength of the interference signal to a ultra-wideband signal received by the second antenna; and

cause the interference signal and the ultra-wideband signal received by the second antenna to be summed in opposition to the first signal in an instance in which the first ratio is greater than a second ratio of a signal strength of the interference signal to a ultra-wideband signal received by the first antenna; and

the combiner further configured to:

combine the first signal with the summed interference signal and the ultra-wideband signal to enable cancellation of the interference signal.

2. The UWB receiver of claim 1 wherein the first antenna is positioned in a first direction to receive signals transmitted from a monitored region and the second antenna is positioned in a second direction, different from the first direction, to receive signals transmitted from outside the monitored region.

3. The UWB receiver of claim 1 wherein the first component of the interference signal and the second component of the interference signal are generated by one or more communications systems positioned outside of a monitored region.

4. The UWB receiver of claim 1 further comprising:

a superheterodyne receiver, the superheterodyne receiver comprising a narrowband bandpass filter and a detector, the superheterodyne receiver is configured to detect whether at least the second component of the interference signal exceeds the threshold level.

5. The UWB receiver of claim 1 further comprising:

a low noise amplifier; and

a bandpass filter;

the low noise amplifier configured to:

add a predetermined gain to the first signal; and

provide the added gain first signal to the bandpass filter;

the bandpass filter configured to:

filter the added gain first signal to pass frequencies in a UWB frequency band comprising the UWB signal and attenuate frequencies outside the UWB frequency band; and

provide the filtered first signal to the combiner.

6. A method comprising:

receiving a first signal from a first antenna, the first signal comprising a UWB signal and a first component of an interference signal;

receiving a second signal from a second antenna, the second signal comprising at least a second component of the interference signal;

combining, at a combiner, the first signal and the second signal to generate an output signal providing cancellation of at least part of the first component of the inference signal based at least in part on the second component of the interference signal;

determining, by a controller, a first ratio of a signal strength of the interference signal of the second signal to a ultra-wideband signal of the second signal;

causing the interference signal and the ultra-wideband signal of the second signal to be summed in opposition to the first signal in an instance in which the first ratio is greater than a second ratio of a signal strength of the interference signal of the first signal to the ultra-wideband signal of the first signal; and

combining, at the combiner, the first signal with the summed interference signal and the ultra-wideband signal of the second signal to enable cancellation of the interference signal.

7. The method of claim 6 further comprising:

modifying, by a variable attenuator and a variable phase shifter, the second signal received from the second antenna; and

providing the modified second signal to the combiner for combining with the first signal.

8. The method of claim 7 further comprising:

receiving, at a detector, the output signal of the combiner, and

generating an indication of an interference level associated with the output signal;

monitoring, by a controller, the interference level associated with the output signal; and

adjusting, by the controller, at least one of a variable attenuator and a variable phase shifter in an instance in which the monitored interference level is above a threshold level.

9. The method of claim 8 further comprising detecting, via a superheterodyne receiver, whether at least the second component of the interference signal exceeds the threshold level.

10. The method of claim 6 wherein the first antenna is positioned in a first direction to receive signals transmitted from a monitored region and the second antenna is positioned in a second direction, different from the first direction, to receive signals transmitted from outside the monitored region.

11. The method of claim 6 wherein the first component of the interference signal and the second component of the interference signal are generated by one or more communications systems positioned outside of a monitored region.

12. The method of claim 6 further comprising:

adding a predetermined gain to the first signal;

filtering the added gain first signal to pass frequencies in a UWB frequency band comprising the UWB signal and attenuating frequencies outside the UWB frequency band; and

providing the filtered first signal to the combiner.

13. An ultra-wideband (UWB) system comprising:

one or more UWB transmitters, each configured to transmit a UWB signal; and

one or more UWB receivers, the one or more UWB receivers comprising:

a first antenna configured to receive a first signal, the first signal comprising the UWB signal and a first component of an interference signal;

a second antenna configured to receive a second signal, the second signal comprising at least a second component of the interference signal;

a combiner configured to:

receive the first signal from the first antenna;

receive the second signal from the second antenna; and

combine the first signal and the second signal to generate an output signal providing cancellation of at least part of the first component of the inference signal based at least in part on the second component of the interference signal;

a detector configured to:

receive the output signal of the combiner; and

indicate an interference level associated with the output signal;

a controller configured to:

monitor the interference level associated with the output signal; and

adjust at least one of a variable attenuator and a variable phase shifter in an instance in which the monitored interference level is above a threshold level;

the variable attenuator and the variable phase shifter configured to:

modify the second signal received from the second antenna; and

provide the modified second signal to the combiner

the controller further configured to:

determine a first ratio of a signal strength of the interference signal to a ultra-wideband signal received by the second antenna; and

cause the interference signal and the ultra-wideband signal received by the second antenna to be summed in opposition to the first signal in an instance in which the first ratio is greater than a second ratio of a signal strength of the interference signal to a ultra-wideband signal received by the first antenna; and

the combiner further configured to:

combine the first signal with the summed interference signal and the ultra-wideband signal to enable cancellation of the interference signal.

14. The UWB system of claim 13 wherein the first antenna is positioned in a first direction to receive signals transmitted from a monitored region and the second antenna is positioned in a second direction, different from the first direction, to receive signals transmitted from outside the monitored region.

15. The UWB system of claim 13 wherein the first component of the interference signal and the second component of the interference signal are generated by one or more communications systems positioned outside of a monitored region.

16. The UWB system of claim 13 wherein the one or more UWB receivers further comprise a superheterodyne receiver, the superheterodyne receiver comprising a narrowband bandpass filter and a detector, the superheterodyne receiver is configured to detect whether at least the second component of the interference signal exceeds the threshold value.