A node is provided that is configured to communicate in a cooperative broadcast multi-hop network that employs broadcast flood routing and multi-hop transmission using a direct-sequence spread-spectrum (DSSS) waveform. The node includes an antenna and a waveform module having a receiver processing chain. The antenna can receive a plurality of DSSS signals from other nodes on a particular channel, and output a channel that includes the plurality of DSSS signals. The plurality of DSSS signals include transmissions that are directly received from other nodes and multi-path components of those transmissions. The receiver processing chain can include a multi-user RAKE receiver that can combine, when performing demodulation processing, a plurality of transmissions directly received from the other nodes and multipath components of transmissions received from the other nodes. In some implementations, the node can perform cooperative beamforming and adaptive space-spectrum whitening.

A receiver is provided that includes a multi-user RAKE receiver that can receive a plurality of transmissions directly received from a plurality of nodes of a cooperative broadcast multi-hop network and multipath components of those transmissions, a combiner module and a data despreader module. The multi-user RAKE receiver includes correlator blocks for each node and a finger selection module. Each correlator block generates one or more candidate fingers for that particular node. The finger selection module can select a subset of the candidate fingers having sufficient correlation for further processing. The combiner module can combine aligned symbols for the subset of candidate fingers to generate and combine soft decisions across each of a plurality of channels into a joint soft decision. The data despreader module can despread chips of information from each of the plurality of channels to generate demodulated data symbols that are converted into data soft-decision bits.

A node is provided for a cooperative broadcast multi-hop network that employs broadcast flood routing and multi-hop transmission. The node includes antennas and a waveform module having a receiver processing chain that can include an adaptive space-spectrum whitener (ASSW) module and a multi-user RAKE (mRAKE) receiver. Each antenna can receive output a channel that includes direct-sequence spread-spectrum signals received from other nodes and multi-path components of those transmissions. The ASSW module can perform adaptive space-spectrum whitening to detect and remove interference signals received from each of the channels by performing a covariance analysis to generate channelized signals. The ASSW module can include modified Discrete Fourier Transform (MDFT) analysis and synthesis modules that generate an interference mitigated time-domain channelized signals. The mRAKE receiver, when performing demodulation processing, can combine the interference mitigated time-domain channelized signals to generate fingers that combine components of transmissions received from the other nodes.

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 method and system of communicating between a plurality of nodes are provided. The plurality of nodes are part of a cooperative broadcast multi-hop network that employs broadcast flood routing and multi-hop transmission using a direct-sequence spread-spectrum (DSSS) waveform.

Disclosed herein are a method for eliminating passive intermodulation distortion (PIMD) and an antenna apparatus using the same. According to an embodiment, the antenna apparatus includes a main antenna used for transmission and reception of an RF signal; an auxiliary antenna used for reception of an RF signal; and a passive intermodulation distortion (PIMD) eliminator configured to calculate PIMD contained in a received signal of the main antenna using a received signal of the auxiliary antenna, and to eliminate the calculated PIMD from the received signal of the main antenna.

A receiver is provided that includes a multi-user RAKE receiver that can receive a plurality of transmissions directly received from a plurality of nodes of a cooperative broadcast multi-hop network and multipath components of those transmissions, a combiner module and a data despreader module. The multi-user RAKE receiver includes correlator blocks for each of the plurality of nodes and a finger selection module. Each correlator block generates one or more candidate fingers for that particular node. The finger selection module can select a subset of the candidate fingers having sufficient correlation for further processing. The combiner module can combine aligned symbols for each of the subset of candidate fingers to generate and combine soft decisions across each of the channels into a joint soft decision. The data despreader module can despread and convert chips from respective data channels to generate demodulated data symbols that are converted into data soft-decision bits.

Techniques for computing electrical phase of electrical metering devices are described. In an example, data indicating zero-crossing times at first and second metering devices is obtained. A time-difference between the zero-crossing times may be determined. In a first example, the time-difference may be based at least in part on calculations involving a first value of a first free-run timer on a first metering device, a second value of a second free-run timer on a second metering device, and a time of a transmission between the metering devices. In a second example, the time-difference may be based at least in part on calculations involving a start or end time of a time-slot of a spread spectrum radio frequency transmission scheme. A phase difference between the first zero-crossing and the second zero-crossing may be determined, based at least in part on the determined time-difference.

A communication device may include a communication interface configured to receive signals and a controller configured to: receive an input signal based on the received signals; perform transform operations on the input signal to generate a spectral periodogram of the input signal; calculate spectral vector powers for each bin of a plurality of bins of the spectral periodogram; determine a median spectral power for a selected range of bins of the plurality of bins; generate a median-scaled spectral density vector based on the median spectral power and a reference spectral density of an expected signal; calculate a detection threshold vector based at least in part on the median-scaled spectral density vector; and identify one or more interference-including bins of the plurality of bins of the spectral periodogram by comparing the spectral vector powers for each bin of the plurality of bins to the detection threshold vector.

A cooperative broadcast multi-hop network that employs broadcast flood routing and multi-hop transmission using a direct-sequence spread-spectrum (DSSS) waveform with cooperative beamforming and adaptive space-spectrum whitening are provided.