摘要:
A method for monitoring feedback loop stability in a wireless repeater includes measuring a gain control metric in the feedback loop of the repeater periodically for a given time period where the gain control metric is indicative of a loop gain of the feedback loop of the repeater; and monitoring the magnitude of the gain control metric to determine the stability of the feedback loop of the repeater. In operation, a large magnitude of the gain control metric indicates instability in the feedback loop of the repeater.
摘要:
A wireless repeater includes a channel estimation block to estimate a feedback channel between the antennas of the repeater using frequency domain channel estimation. The repeater includes a pilot signal blanking circuit to blank out a selected number of samples of the pilot signal to improve the accuracy of the channel estimation. In another embodiment, the repeater replaces T samples of the pilot signal with a cyclic prefix.
摘要:
A wireless repeater introduces a low level noise to the signal path of the repeater where the introduced noise is used to facilitate channel estimation. The introduced low power level noise may be added to the receive signal or to the transmit signal. The low power noise signal ensures that the repeater always has a reference signal for performing channel estimation, even when the repeater is not receiving any incoming signal traffic. In one embodiment, a low noise signal is inserted to the transmit circuit of the repeater. In another embodiment, the repeater is configured to increase the noise figure of the receive circuit where the detected noise figure acts as a receive signal.
摘要:
In an embodiment, a first repeater configures a beacon signal that identifies the first repeater to one or more other repeaters. The first repeater transmits the configured beacon signal at a given transmission power level to the one or more other repeaters. The transmitted beacon signal is received at least by a second repeater. The second repeater reduces interference associated with other transmissions from the first repeater, such as retransmissions of donor signals, based on the received beacon signal.
摘要:
Methods and apparatus for estimating a loop delay value (Ndelay) in an interference cancellation repeater are presented. For example, a method may include setting a repeater gain to an initial gain value, setting a delay parameter to an initial time value, and measuring a loop gain associated with the delay parameter and the repeater gain by detecting a feedback signal with an echo canceller disabled. The method may further include determining whether the measured loop gain is larger than a previously measured loop gain, and if so, designating the delay parameter as the loop delay value (Ndelay); and decrementing the delay parameter when the measured loop gain is not larger than the previously measured loop gain, and when the delay parameter is not at a final time value. The method may iterate until the delay parameter is less than or equal to the final time value.
摘要:
A method for controlling gain in a wireless repeater includes computing a gain control metric indicative of a loop gain of the repeater and detecting changes in a signal power of a gain control input signal where the gain control input signal is taken from any point in the feedback loop of the repeater. When a large power swing in the gain control input signal is detected, the method operates to discard at least a portion of each gain control metric measurement for a first duration before continuing with computing the gain control metric. In another embodiment, the method may include discarding samples of the gain control input signal used in computing the gain control metric for a first duration when a large power swing in the gain control input signal is detected.
摘要:
A wireless repeater includes a channel estimation block to estimate a feedback channel between the antennas of the repeater using frequency domain channel estimation. The repeater includes a pilot signal blanking circuit to blank out a selected number of samples of the pilot signal to improve the accuracy of the channel estimation. In another embodiment, the repeater replaces T samples of the pilot signal with a cyclic prefix.
摘要:
A wireless repeater having a receiving antenna for receiving an input signal and a transmitting antenna for transmitting an amplified signal includes first and second front-end circuits and a repeater baseband block coupled between the first and second front-end circuits. The repeater baseband block includes a channel estimation block, an echo canceller implementing time domain echo cancellation, a variable gain stage controlled by a gain control block implementing digital gain control, a first variable delay element introducing a first delay before or after the echo canceller, a second variable delay element introducing a second delay to the output signal. The delayed output signal is coupled to the channel estimation block as a reference signal for estimating the feedback channel, to the echo canceller as a reference signal for estimating the feedback signal, and to the gain control block for monitoring the stability of the repeater.
摘要:
A method for controlling gain in a wireless repeater includes computing a gain control metric indicative of a loop gain of the repeater and detecting changes in a signal power of a gain control input signal where the gain control input signal is taken from any point in the feedback loop of the repeater. When a large power swing in the gain control input signal is detected, the method operates to discard at least a portion of each gain control metric measurement for a first duration before continuing with computing the gain control metric. In another embodiment, the method may include discarding samples of the gain control input signal used in computing the gain control metric for a first duration when a large power swing in the gain control input signal is detected.
摘要:
A wireless repeater incorporates a gain management block to implement a multi-parameter gain management algorithm. The gain management algorithm receives gain settings from at least a gain control metric for stability and output signal quality and signal headroom values associated with circuitry of the repeater. The gain management block provides secure and robust boot-up of the repeater as well as oscillation detection and prevention. Furthermore, the gain management block implements repeater stability control, output signal-to-noise level control, uplink and downlink gain balance control and compensation for device constraints.