Various operations may be performed based on a distance-related function associated with two or more devices. For example, an association procedure for two or more devices may be based on one or more determined distances. Similarly, presence management may be based on one or more determined distances. A distance-related function may take various form including, for example, a distance between devices, two or more distances between devices, a rate of change in a relative distance between devices, relative acceleration between devices, or some combination of two or more of the these distance-related functions.

A non-multiply-accumulate (non-MAC) charge-based analog correlator system including a sampler circuit block, an operand generation circuit block, and a margin propagation (MP) correlation computation circuit block is disclosed. The sampler circuit block is configured to sample a plurality of input analog signals. The operand generation circuit block is configured to generate operands based on the sampled plurality of input analog signals, and the margin propagation (MP) correlation computation circuit block is configured to generate correlated output signals based on the operands and using calculations in a charge domain.

Methods and devices for estimating an angle between a transmitter and a receiver for beamforming are provided. A method includes, with an antenna element in a first device, transmitting an omnidirectional pulse and detecting an echo of the pulse reflected from a second device. An angle between the first device and the second device is estimated based at least on a characteristic of the echo. The method includes transmitting the angle to the second device for use in beamforming between the first device and the second device.

A radar apparatus includes an antenna that receives echo signals, each of the echo signals being a radar signal reflected by one or more objects; a Doppler-frequency acquirer that acquires Doppler frequencies at each range bin from the received echo signals; a direction correlation power-value calculator that calculates direction correlation power values for respective combinations of the Doppler frequencies and at least one of a distance to the one or more objects and an arrival direction of the echo signals, each direction correlation power value indicating a strength of a corresponding echo signal; and a normalized direction correlation-value calculator that calculates, for the respective combinations, normalized direction correlation values, each normalized direction correlation value indicating a probability of the arrival direction of the corresponding echo signal.

A radar device includes: a transmission beam controller that selects, every first period, a transmission beam set used for transmission of a radar signal from among a plurality of transmission beam sets each including at least two transmission beam directions; and a radar transmitter that transmits the radar signal in a predetermined transmission period by using the selected transmission beam set, wherein the transmission beam controller switching, every second period within the first period, among the at least two transmission beam directions included in the transmission beam set.

To reduce radar cells and to improve the detection of a radar system, particularly a high-frequency surface wave radar (HFSWR), the broadcast system (SEM) is capable of broadcasting basic orthogonal signals two by two and each orthogonal to itself, temporally shifted to form, respectively, broadcast radiation patterns, each including main radiation lobes (LP.sub.1, LP.sub.N) alternating with secondary lobes, the main lobes associated with the basic signals being substantially juxtaposed in space. The receiving system (SRE) is capable of forming as many reception patterns in a monitored receiving area (ZR) as cells (CES.sub.n'm) contained in the receiving area that are covered by main radiation lobes (LP.sub.n) from one of the broadcast radiation patterns and located at a bistatic distance from the broadcast and receiving systems.

Systems, methods, and apparatus for transmitting and receiving signals are disclosed. In one or more embodiments, the disclosed method involves splitting a signal into low power portions. The method further involves coding the low power portions to produce coded low power portions, where the coding comprises convolving each low power portion with a respective different code. Also, the method involves summing the coded low power portions to produce a resultant coded signal. In addition, the method involves transmitting the resultant coded signal towards a target object. Additionally, the method involves receiving a reflected resultant coded signal, where the resultant coded signal reflects off the target object to produce the reflected resultant coded signal. Also, the method involves decoding the reflected resultant coded signal to produce a decoded signal. Further, the method involves correlating the decoded signal to produce a complete received signal.

A system, apparatus, and method for receiving a signal. In one implementation, the system includes a receiver, a correlator, and a range sidelobe envelope generator. The receiver receives the signal. The correlator compresses the signal with a reference signal. The range sidelobe envelope generator generates a range sidelobe envelope function based on the compressed signal.

A radar device includes: radar transmitting circuitry which, in operation, generates Nt radar signals by modulating Nt transmission code sequences and transmits the radar signals via Nt transmission antennas, Nt being more than 1; and radar receiving circuitry which, in operation, receives reflection wave signals via Nr reception antennas and performs Doppler frequency analysis, Nr being more than 1. The radar transmitting circuitry stores a predetermined pulse sequence and Nt or more orthogonal code sequences, second half elements of the Nt or more orthogonal code sequences are arranged in an order reverse to first half elements of the Nt or more orthogonal code sequences and generates each of the Nt transmission code sequences by multiplying elements of the predetermined pulse sequence by elements of the Nt or more orthogonal code sequences different from each other.

A pulse transmission controller generates transmission timing signals for a high-frequency radar transmission signal in every transmission cycle. A transmission phase shifter gives a transmission signal generated by a modulator phase shifts each corresponding to a transmission cycle on the basis of the transmission timing signals generated at intervals that are equal to the transmission cycle. A reception phase shifter gives a reception signal that is output from an A/D converter reception phase shifts that are opposite in direction to the respective transmission phase shifts given by the transmission phase shifter on the basis of the transmission timing signals generated at intervals that are equal to the transmission cycle.