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:
A device for generating a pilot signal for use in a wireless repeater where the pilot signal is added to a transmit signal for transmission includes a pilot power control unit configured to set a power level of the pilot signal as a function of a gain of the repeater and a power level of the transmit signal, where the function comprises a linear or non-linear function. In one embodiment, the operation of the repeater may be divided into gain regions and the inserted pilot power is controlled according to the different gain regions of the repeater. When the repeater gain is low, the pilot power may be set greater than the transmit power to ensure there is sufficient signal to use for channel estimation. When the repeater gain is in steady state, the pilot power may be set to be lower than the transmit power to avoid interference.
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:
In one embodiment, a device for constructing a pilot signal for use in a wireless repeater where the pilot signal is added to a transmit signal includes one or more pilot generators. Each pilot generator generates a carrier pilot signal associated with a single carrier of the transmit signal and the carrier pilot signals generated by the one or more pilot generators are summed to generate the pilot signal. Each of the one or more pilot generators includes a pilot symbol unit providing multiple data symbols having a predetermined data structure as the carrier pilot signal, a pilot scrambler, a filter, a pilot power determination unit, and a cyclic prefix insertion unit for inserting a cyclic prefix, to the carrier pilot signal. In another embodiment, the pilot symbol unit providing multiple data symbols in frequency domain as the carrier pilot signal.
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 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.
摘要:
A wireless repeater in a multi-repeater environment operates to detect the presence of neighboring repeaters and to maintain repeater stability in the presence of a neighboring repeater. In some embodiments, the repeater transmits a known signal sequence to discover the presence of a neighboring repeater. When a neighboring repeater is detected, the repeater may apply mitigation measures to maintain operational stability at the repeater.
摘要:
In one embodiment, a device for constructing a pilot signal for use in a wireless repeater where the pilot signal is added to a transmit signal includes one or more pilot generators. Each pilot generator generates a carrier pilot signal associated with a single carrier of the transmit signal and the carrier pilot signals generated by the one or more pilot generators are summed to generate the pilot signal. Each of the one or more pilot generators includes a pilot symbol unit providing multiple data symbols having a predetermined data structure as the carrier pilot signal, a pilot scrambler, a filter, a pilot power determination unit, and a cyclic prefix insertion unit for inserting a cyclic prefix to the carrier pilot signal. In another embodiment, the pilot symbol unit providing multiple data symbols in frequency domain as the carrier pilot signal.