Systems and methods for adjusting system tests based on detected interference
View Patent ↗Embodiments of the present invention provide improved systems and methods for adjusting system tests based on detected interference. In one embodiment, a system comprises a host unit; a system test controller to control the performance of system tests, wherein a system test to detect the reception of an interfering signal comprises disabling the generation of tones for transmission through the communication system. The system also comprises multiple remote antenna units communicatively coupled to the system test controller to transmit signals to multiple wireless terminals, wherein a remote antenna unit comprises: an antenna; a transceiver, coupled to the antenna; a signal detector that measures reverse and forward power of signals transmitted to and received from the antenna; and a microcontroller to control the antenna unit, wherein upon receiving a command to perform interference testing, the microcontroller adjusts a subsequent test based on measurements of the reverse power by the signal detector.
1. A method for testing a distributed antenna system (DAS), the method comprising:
disabling generation of at least one tone, where the at least one tone is transmitted to a remote antenna unit;
measuring at least one of the reverse power and the forward power at the remote antenna unit;
determining whether the remote antenna unit is receiving an interfering signal based on at least one of the measured reverse power and the measured forward power; and
adjusting at least one subsequent system test based on the determination of whether the remote antenna unit is receiving an interfering signal.
2. The method of claim 1 , wherein adjusting the at least one subsequent test comprises at least one of:
adjusting the performance of a system test to detect a disconnected antenna; and
adjusting the performance of gain calibration.
3. The method of claim 2 , wherein adjusting the performance of gain calibration comprises preventing the remote antenna unit from adjusting the gain for signals transmitted by the antenna unit.
4. The method of claim 3 , wherein adjusting the performance of gain calibration comprises:
alternating the generation and disablement of the at least one tone;
measuring the reverse power with the at least one signal detector.
calculating a difference between the measured reverse power when the at least one tone is generated and the measured reverse power when the at least one tone is disabled;
subtracting the difference from the measured reverse power when the at least one tone is generated; and
setting the gain of the remote antenna unit based on the result of the subtraction.
5. The method of claim 2 , wherein adjusting the performance of a system test to detect a disconnected antenna comprises:
alternating the generation and disablement of the at least one tone;
measuring the reverse power with the at least one signal detector.
calculating a difference between the measured reverse power when the at least one tone is generated and the measured reverse power when the at least one tone is disabled;
subtracting the difference from the measured reverse power when the at least one tone is generated; and
determining whether an antenna is connected based on the result of the subtraction.
6. The method of claim 1 , further comprising setting an alarm based on the determination of whether the remote antenna unit is receiving an interfering signal.
7. The method of claim 1 , further comprising measuring the reverse power and the forward power multiple times when the generation of the at least one tone is disabled to form a reverse power measurement set and a forward power measurement set.
8. The method of claim 7 , wherein the multiple measurements are gathered sporadically.
9. The method of claim 7 , further comprising:
calculating a reverse power average from a subset of the reverse power measurement set and a forward power average from a subset of the forward power measurement set; and
comparing the reverse power average against the forward power average.
10. The method of claim 9 , wherein the reverse power samples in the subset of the reverse power measurement set are associated with forward power samples in the subset of the forward power measurement set.
11. The method of claim 1 , wherein determining whether the remote antenna unit is receiving the interfering signal based on the measured reverse power and the measured forward power comprises determining whether a measured reverse power exceeds an interference threshold, wherein the interference threshold is a signal power level between an antenna disconnect alarm threshold and a noise floor for the at least one signal detector.
12. The method of claim 1 , wherein determining whether the remote antenna unit is receiving the interfering signal based on the measured reverse power and the measured forward power comprises determining whether the measured reverse power exceeds the measured forward power by a predetermined power level.
13. An antenna unit, the antenna unit comprising:
at least one antenna;
a transceiver, coupled to the at least one antenna;
at least one signal detector that measures reverse power and forward power of signals transmitted to and received from the at least one antenna; and
a microcontroller configured to control the operation of the antenna unit, wherein upon receiving a command from a system test controller to perform interference testing, the microcontroller directs the at least one signal detector to measure the reverse power of signals passing through the antenna unit when the antenna unit is not receiving a tone for transmission to the at least one antenna, wherein the microcontroller adjusts at least one subsequent test based on the measured reverse power.
14. The antenna unit of claim 13 , wherein adjusting the at least one subsequent test comprises at least one of:
adjusting the performance of a system test to detect a disconnected antenna when the difference between the measured reverse power and the measured forward power exceeds an interference threshold; and
adjusting the performance of gain calibration.
15. The antenna unit of claim 14 , wherein adjusting the performance of gain calibration comprises preventing the antenna unit from adjusting the gain for signals transmitted by the antenna unit.
16. The antenna unit of claim 14 , wherein adjusting the performance of gain calibration comprises:
measuring reverse power in the presence of a calibration tone and without the presence of the calibration tone;
calculating a difference between the measured reverse power in the presence of the calibration tone and the measured reverse power without the presence of the calibration tone;
subtracting the difference from the measured reverse power with the presence of the calibration tone; and
setting the gain of the antenna unit based on the result of the subtraction.
17. The antenna unit of claim 14 , wherein the interference threshold is a signal power level between an antenna disconnect alarm threshold and a noise floor for the at least one signal detector.
18. The antenna unit of claim 13 , wherein the antenna unit sets an alarm based on the difference between the reverse power and the forward power.
19. The antenna unit of claim 13 , wherein a signal detector in the at least one signal detector is dedicated to measuring reverse power and forward power in a specific communication band.
20. The antenna unit of claim 13 , wherein the at least one signal detector gathers multiple measurements of the reverse power and the forward power multiple times to form a reverse power measurement set and a forward power measurement set during the interference testing.
21. The antenna unit of claim 20 , wherein the multiple measurements are gathered sporadically during the interference testing.
22. The antenna unit of claim 20 , wherein measuring the reverse power of signals passing through the antenna unit when the antenna unit is not receiving a tone for transmission comprises:
creating a reverse power average from a subset of the reverse power measurement set and a forward power average from a subset of the forward power measurement set; and
comparing the reverse power average against the forward power average.
23. The antenna unit of claim 20 , wherein a reverse power measurement and a forward power measurement in the multiple measurements of the reverse power and the forward power are associated with one another.
24. The antenna unit of claim 13 , wherein adjusting at least one subsequent system test comprises adjusting the at least one subsequent system test when the measured reverse power exceeds the forward power by a predetermined power level.
25. The antenna unit of claim 13 , wherein the antenna unit is a remote antenna unit in a distributed antenna system.
26. A communication system comprising:
a host unit;
at least one system test controller configured to control the performance of system tests on the communication system, wherein the at least one system test controller performs a test to detect the reception of an interfering signal comprising disabling the generation of tones for transmission through the communication system; and
a plurality of remote antenna units communicatively coupled to the at least one system test controller configured to communicatively transmit signals to a plurality of wireless terminals, wherein a remote antenna unit in the plurality of remote antenna units comprises:
at least one antenna;
a transceiver, coupled to the at least one antenna;
at least one signal detector that measures reverse power and forward power of signals transmitted to and received from the at least one antenna; and
a microcontroller configured to control the operation of the antenna unit, wherein upon receiving a command from the system test controller to perform interference testing, the microcontroller adjusts at least one subsequent test based on measurements of the reverse power by the at least one signal detector.
27. The communication system of claim 26 , wherein the plurality of remote antenna units comprises at least one master remote antenna unit and at least one slave remote antenna unit, wherein the tones generated by the at least one system test controller are transmitted to the at least one master remote antenna unit, and from the at least one master remote antenna unit to the at least one slave remote antenna unit.