An interference wave signal frequency is highly accurate and the interference wave signal is surely removed. A controller of an interference wave signal remover detects the interference wave signal based on a frequency scanning result by an entire-range frequency scanner, and sets a notch filter to attenuate the interference wave signal frequency. A local scan frequency band BWf.sub.L of a local frequency scanner is set by having the interference wave signal frequency as its central frequency, and local scan frequencies BIN.sub.L are set so that frequency bands overlap with each other between adjacent frequency BIN.sub.A. The local frequency scanner frequency-scans input signals to the notch filter. The controller calculates a frequency error δf of the interference wave signal frequency from the local frequency scanner, corrects the interference wave signal frequency which is from the entire-range frequency scanner by the frequency error δf, and updates the setting of the notch filter.

A method that incorporates aspects of the subject disclosure may include, for example, receiving digital data via a plurality of fiber optic cables, wherein the digital data represents a plurality of radio frequency signals received at a plurality of remote radio units via a plurality of uplink paths, wherein the first virtual processing system is configured to mitigate interference detected in one or more of the plurality of uplink paths, performing a plurality of measurements of the digital data to identify an interference condition associated with at least a portion of the plurality of uplink paths associated with the plurality of remote radio units; and providing updated digital data, according to the interference condition that is identified, to a second virtual processing system including at least one second virtual processor, wherein the second virtual processing system is configured to operate as one or more baseband units for providing cellular communication services. Other embodiments are disclosed.

A method that incorporates aspects of the subject disclosure may include, for example, receiving digital data via a plurality of fiber optic cables, wherein the digital data represents a plurality of radio frequency signals received at a plurality of remote radio units via a plurality of uplink paths, wherein the first virtual processing system is configured to mitigate interference detected in one or more of the plurality of uplink paths, performing a plurality of measurements of the digital data to identify an interference condition associated with at least a portion of the plurality of uplink paths associated with the plurality of remote radio units; and providing updated digital data, according to the interference condition that is identified, to a second virtual processing system including at least one second virtual processor, wherein the second virtual processing system is configured to operate as one or more baseband units for providing cellular communication services. Other embodiments are disclosed.

In an ultra-wideband (“UWB”) receiver, a received UWB signal is periodically digitized as a series of ternary samples. The samples are continuously correlated with a predetermined preamble sequence to develop a correlation value. When the value exceeds a predetermined threshold, indicating that the preamble sequence is being received, a stream of estimates of the channel impulse response (“CIR”) are developed. When a start-of-frame delimiter (“SFD”) is detected, the best CIR estimate is provided to a channel matched filter (“CMF”) substantially to filter channel-injected noise. The time of arrival of the first arriving path is developed from the stream of CIR estimates.

In an ultra-wideband (“UWB”) receiver, a received UWB signal is periodically digitized as a series of ternary samples. The samples are continuously correlated with a predetermined preamble sequence to develop a correlation value. When the value exceeds a predetermined threshold, indicating that the preamble sequence is being received, a stream of estimates of the channel impulse response (“CIR”) are developed. When a start-of-frame delimiter (“SFD”) is detected, the best CIR estimate is provided to a channel matched filter (“CMF”) substantially to filter channel-injected noise. The time of arrival of the first arriving path is developed from the stream of CIR estimates.

A direct sequence spread spectrum (DSSS) receiver includes an antenna, signal-to-noise ratio (SNR) estimation logic, and preamble detection logic. The antenna is configured to receive a DSSS signal. The SNR estimation logic is configured to estimate SNR of the received DSSS signal. The preamble detection logic is configured to, in response to the SNR estimate exceeding a SNR threshold value, detect a preamble sequence in the DSSS signal based on an absolute value of a sequence of correlation values. The sequence of correlation values is a complex quantity.

A direct sequence spread spectrum (DSSS) receiver includes an antenna, signal-to-noise ratio (SNR) estimation logic, and preamble detection logic. The antenna is configured to receive a DSSS signal. The SNR estimation logic is configured to estimate SNR of the received DSSS signal. The preamble detection logic is configured to, in response to the SNR estimate exceeding a SNR threshold value, detect a preamble sequence in the DSSS signal based on an absolute value of a sequence of correlation values. The sequence of correlation values is a complex quantity.

The present technology relates to a signal processing apparatus and method which are able to suppress a reduction in reception sensitivity. A reception signal is compressed so as to have a predetermined signal level or lower, and transmission data transmitted from a transmitter side and included in the reception signal compressed so as to have the signal level or lower is decoded. For example, an approximate replica signal reproducing large amplitude changes of the reception signal is generated, and the approximate replica signal is subtracted from the reception signal to compress the reception signal so as to have the signal level or lower. The present disclosure is applicable to, for example, a signal processing apparatus, a reception apparatus, a transmission/reception apparatus, a communication apparatus, an information processing apparatus, an electronic device, a computer, a program, a storage medium, a system, and so on.

A system that incorporates aspects of the subject disclosure may perform operations including, for example, obtaining uplink information associated with a plurality of communication devices transmitting wireless signals on a plurality of uplink paths, performing, based on the uplink information, a plurality of measurements of the plurality of uplink paths, identifying a measurement from the plurality of measurements that is below a threshold, and initiating a corrective action to improve a measurement of an affected uplink path of the plurality of uplink paths based on the identifying. Other embodiments are disclosed.

A system that incorporates aspects of the subject disclosure may perform operations including, for example, obtaining uplink information associated with a plurality of communication devices transmitting wireless signals on a plurality of uplink paths, performing, based on the uplink information, a plurality of measurements of the plurality of uplink paths, identifying a measurement from the plurality of measurements that is below a threshold, and initiating a corrective action to improve a measurement of an affected uplink path of the plurality of uplink paths based on the identifying. Other embodiments are disclosed.