A shared radar and communications system. The system includes a transmitter and a receiver. The transmitter modules signals based on a first spreading code defined at least in part by a first plurality of information bits. The first plurality of information bits encodes selected information. The transmitter transmits the modulated signals. The receiver receives a first signal and a second signal. The first signal includes the transmitted signals transmitted by the transmitter and reflected from objects in an environment. The receiver processes the first signal to detect objects in the environment. The second signal is transmitted from another system. The second signal carries a second plurality of information bits. The receiver processes the second signal to determine the second plurality of information bits. The second plurality of information bits are encoded with information selected by the other system.

A method of compensating for IQ mismatch (IQMM) in a transceiver may include sending first and second signals from a transmit path through a loopback path, using a phase shifter to introduce a phase shift in at least one of the first and second signals, to obtain first and second signals received by a receive path, using the first and second signals received by the receive path to obtain joint estimates of transmit and receive IQMM, at least in part, by estimating the phase shift, and compensating for IQMM using the estimates of IQMM. Using the first and second signals received by the receive path to obtain estimates of the IQMM may include processing the first and second signals received by the receive path as a function of one or more frequency-dependent IQMM parameters.

Systems and methods for classifying radio frequency signal modulations include receiving, at a consolidated neural network, a complex quadrature vector of interest representative of a baseband signal derived from a radio frequency signal, generating multiple data representations of the vector of interest, providing each data representation to one of multiple parallel neural networks in the consolidated neural network, and receiving, from the consolidated neural network, a classification result for the baseband signal. The consolidated neural network may be trained to classify baseband signals with respect to known modulation types by receiving complex quadrature training vectors, each including samples of a baseband signal derived from a radio frequency signal of known modulation type, comparing a classification result for the training vector to the known modulation type to determine modulation classification performance, and modifying a configuration parameter of the consolidated neural network dependent on the determined modulation classification performance.

Methods, devices and systems that use a control channel to coordinate quality of data communications in software-defined heterogenous multi-hop ad hoc networks are described. In some embodiments, an example apparatus for wireless communication in a network includes performing, using a control plane, network management functions over a control channel that has a first bandwidth, implements a frequency-hopping operation, and operates at in a first frequency band, and performing, using a data plane that is physically and logically decoupled from the control plane, data forwarding functions, based on a routing decision, over at least one data channel that has a second bandwidth and operates in a second frequency band different from the first frequency band.

A method to generate a wireless waveform for use in a wireless communication system, a wireless communication system and computer program product thereof

The method comprises the generation of a waveform for application in the wireless communication system characterized by significant phase noise, Doppler spread, multipath, frequency instability, and/or low power efficiency by at the transmitter side: creating a discrete-time instantaneous frequency signal {tilde over (f)}[n]; appending a cyclic prefix with length L.sub.CP to the beginning of the discrete-time instantaneous frequency signal {tilde over (f)}[n]; constructing a discrete-time unwrapped instantaneous phase φ[n]; constructing a discrete-time complex baseband signal, and appending at the beginning a Constant Amplitude Zero Autocorrelation, CAZAC, signal of length L.sub.CP for multipath detection; and passing the constructed discrete-time complex baseband signal through a digital-to-analog, DAC, converter to yield the continuous-time radio frequency signal s(t) after conversion to the carrier frequency.

Systems and methods are disclosed for producing a cyclically generated, continuous-phase, frequency-shift keying (CG-CPFSK) waveform which may be used for wired and/or wireless communication systems. Such waveforms may have a substantially constant modulus and have an underlying cyclic phase structure. Systems and methods are also disclosed for generating a waveform based on a cyclically continuous signal which may be subsequently translated into a radio frequency for transmission.

A transmitting device (20) overlays control information onto information bit stream intended for a receiving device (40) by varying or shifting the modulation index in continuous phase modulation (CPM) waveform. The receiving device (40) detects the modulation index used at the transmitting device (20) to modulate the data burst. The receiving device (40) then determines the control information based on the detected modulation index.

A system and method employ an exclusive-OR gate having a first input configured to receive an RF carrier signal having an RF carrier, and a second input configured to receive a square wave signal having a square wave frequency, to output to a signal processing channel under test a binary phase shift keying (BPSK) signal comprising the RF carrier signal modulated by the square wave signal. A digital signal processor is configured to receive from the signal processing channel in-phase (I) and quadrature-phase (Q) data produced by the signal processing channel in response to the BPSK signal, and to process the I and Q data to determine an amplitude response and phase response of the signal processing channel as a function of frequency.

A shared radar and communication system for a vehicle includes capabilities for radar detection and communication with vehicles equipped with similar systems. The radar system is equipped with pluralities of transmit antennas and pluralities of receive antennas. The radar transmits a signal modulated with spread codes that are information bits. A receiver discriminates the signals sent from own transmitters and multiple reflections to detect objects of interest. In addition, the receiver discriminates signals transmitted from different systems on other vehicles. This requires the receiving system to have knowledge of the codes transmitted by the other vehicle. The receiving system determines the information bits sent by the other vehicle. If multiple radar systems on multiple vehicles use different sets of codes (but known to each other), the multiple systems can create a communication infra-structure in addition to radar detection and imaging.

In an embodiment, a receiver detects a timing error between a transmitter clock at a transmitter and a receiver clock at a receiver associated with an exchange of CPM signals. The receiver phase aligns input samples of a candidate received signal over a time window based on a rotating signal corresponding to a phase progression of the candidate received signal. The receiver generates first and second partial sums of the phase-aligned input samples that are accumulations of phase-aligned input samples corresponding to modulation symbols that contribute positive and negative phases, respectively, to the phase progression. The receiver determines a phase difference between the first and second partial sums, and generates a timing-error metric that is indicative of a timing error between the transmitter clock and the receiver clock based at least in part upon the determined phase difference.