Time division duplex (TDD) network protection repeater
A technology is described for a time division duplex (TDD) repeater with network protection. The TDD repeater can comprise a first port, a second port, and one or more amplification paths coupled between the first port and the second port. The TDD repeater can comprise a signal detector configured to measure a received signal power for a downlink (DL) signal in a first set of one or more TDD DL subframes. The TDD repeater can be further configured to adjust an uplink (UL) noise power or gain of the one or more amplification paths based on the received signal power for the DL signal in the first set of the one or more TDD DL subframes.
1. A time division duplex (TDD) repeater comprising:
a first port;
a second port;
one or more amplification paths coupled between the first port and the second port; and
a signal detector configured to measure a power variance for a first-direction signal over multiple non-consecutive first-direction subframes in the first direction signal, and
wherein the repeater is configured to determine that an oscillation may have occurred in the first-direction signal when the power variance is less than a selected threshold; and
wherein the repeater is configured to determine that an oscillation has not occurred in the first-direction signal when the power variance is greater than a selected threshold.
2. The TDD repeater of claim 1 , wherein the repeater is configured to mitigate the oscillation by one or more of:
automatic gain reduction (AGC), or
disable a first-direction transmission for the first-direction signal; or
reduce a gain of the first-direction signal by a predetermined amount.
3. The TDD repeater of claim 1 , wherein the oscillation in the first-direction signal is detected and mitigated when the repeater is in a first-direction mode.
4. The TDD repeater of claim 1 , wherein the repeater is further configured to:
determine a maximum noise power level or maximum gain at which oscillation does not occur;
store the maximum power level or the maximum gain; and
transmit a next subframe after the multiple non-consecutive first-direction subframes in the first direction signal using the stored maximum power level or the stored maximum gain.
5. The TDD repeater of claim 1 , wherein the oscillation is detected and mitigated within a selected time period, wherein the selected time period is:
less than 1 second when the first-direction is a downlink direction, or
less than 0.3 seconds when the first-direction is an uplink direction.
6. The TDD repeater of claim 1 , wherein the power variance for the first-direction signal can be determined from one or more of:
peak-to-minimum power ratio, or
peak-to-average power ratio (PAPR), or
standard deviation, or
peak-to-minimum power difference.
7. A time division duplex (TDD) repeater comprising:
a first port;
a second port;
one or more amplification paths coupled between the first port and the second port; and
a signal detector configured to measure a power variance for a first-direction signal during a longest consecutive set of single-direction subframes that occur in a frame of the first-direction signal, and
wherein the repeater is configured to determine that an oscillation may have occurred in the first-direction signal when the power variance is low; and
wherein the repeater is configured to determine that an oscillation has not occurred in the first-direction signal when the power variance is high.
8. The TDD repeater of claim 7 , wherein the repeater is configured to mitigate the oscillation by one or more of:
automatic gain reduction (AGC), or
disable a first-direction transmission for the first-direction signal; or
reduce a gain of the first-direction signal by a predetermined amount.
9. The TDD repeater of claim 7 , wherein the oscillation in the first-direction signal is detected and mitigated when the repeater is in a first-direction mode.
10. The TDD repeater of claim 7 , wherein the repeater is further configured to:
determine a maximum noise power level or maximum gain at which oscillation does not occur;
store the maximum power level or the maximum gain; and
transmit a next subframe after the longest consecutive set of single-direction subframes in the first direction signal using the stored maximum power level or the stored maximum gain.
11. The TDD repeater of claim 7 , wherein the oscillation is detected and mitigated within a selected time period, wherein the selected time period is:
less than 1 second when the first-direction is a downlink direction, or
less than 0.3 seconds when the first-direction is an uplink direction.
12. The TDD repeater of claim 7 , wherein the power variance for the first-direction signal can be determined from one or more of:
peak-to-minimum power ratio, or
peak-to-average power ratio (PAPR), or
standard deviation, or
peak-to-minimum power difference.