Abstract: A method of generating a reference signal for transmission over a wireless communication channel comprises generating a first signal of a first characteristic, generating a second signal with second characteristic, scaling the second signal at least in time and an amplitude to form a scaled signal and iteratively adding the scaled signal to the first signal to generate the reference signal. The iteratively adding comprises time indexing the first signal with plurality of time points, adding the scaled signal to first signal at each time point in the plurality of time points, computing a cost function to determine the cost of adding the scaled signal at each time point in the plurality of time points, selecting a set of time points that indicate reduction in the cost when the scaled signal is added and adjusting the amplitude of the scaled signal at each time point in the set of time points to reduce the cost.

Abstract: According to an aspect, method in a radar receiver system comprising, receiving a radar signal reflected from a target on a plurality of antennas, wherein the radar signal is a frequency modulated continuous wave (FMCW) signal comprising plurality of chirps, extracting a plurality of range bins from the radar signal, generating a plurality of reference angles and a plurality of reference velocities from a plurality of reference parameters, determining a plurality of reference weights from the plurality of reference angles and plurality of reference velocities, filtering the radar signal with the filter weights set to equal to the plurality of reference weights.

Abstract: A radio frequency receiver comprises a set of antennas for receiving an RF signal over a communication channel represented by a channel matrix Hd, a plurality of analog beamformer for generating plurality of analog beams, wherein each analog beam former is coupled to a subset of antennas comprising a fewer number antennas in the set of antennas, a mixer for combining the plurality of analog beams to provide a down converted signal, and a digital beam former for generating a plurality of digital beams, wherein a set of analog weights (FR) of the plurality of analog beamformer and a set of digital weights (FB) of the digital beamformer are selected such that effective beam formed by their product FB FR is orthogonal and spans the same space as columns of the channel matrix Hd.

Abstract: According to an aspect, a method in a wireless communication receiver comprises receiving a radio frequency (RF) signal, delaying the RF signal with a set of time delays, shifting the RF signal with a set of offset frequencies, compressing in time the RF signal with a set of compression factors, correlating the RF signal after subjecting to said delaying, shifting and compressing in time with a reference signal, and selecting a first delay, first offset frequency, and first compression ratio that corresponds to a peak resulting from said correlating, wherein the said first delay, first offset frequency, and first compression ration representing the difference between the RF signal and the reference signal.

Abstract: A radio frequency receiver comprises a set of antennas for receiving an RF signal over a communication channel represented by a channel matrix Hd, a plurality of analog beamformer for generating plurality of analog beams, wherein each analog beam former is coupled to a subset of antennas comprising a fewer number antennas in the set of antennas, a mixer for combining the plurality of analog beams to provide a down converted signal, and a digital beam former for generating a plurality of digital beams, wherein a set of analog weights (FR) of the plurality of analog beamformer and a set of digital weights (FB) of the digital beamformer are selected such that effective beam formed by their product FB FR is orthogonal and spans the same space as columns of the channel matrix Hd.

Abstract: A method of determining a total delay to a radio frequency (RF) signal caused by a path between a start point and an end point comprising, injecting a plurality of frequency tones at the start point, wherein the frequency tones are of different frequency, receiving the plurality of frequency tones at the end point, measuring a plurality phase differences corresponding to difference of phase between the plurality of frequency tones injected at the start point and the corresponding plurality of the frequency tones received at the end point, and determining a total delay to the RF signal caused by the path from at least more than one of the plurality of phase differences measured. The method further comprises determining a total phase shift to the RF signal from the total delay and a frequency of the RF signal.

Abstract: According to an aspect, a method in a wireless communication receiver comprises receiving a radio frequency (RF) signal, delaying the RF signal with a set of time delays, shifting the RF signal with a set of offset frequencies, compressing in time the RF signal with a set of compression factors, correlating the RF signal after subjecting to said delaying, shifting and compressing in time with a reference signal, and selecting a first delay, first offset frequency, and first compression ratio that corresponds to a peak resulting from said correlating, wherein the said first delay, first offset frequency, and first compression ration representing the difference between the RF signal and the reference signal.

Abstract: According to an aspect, method in a radar receiver system comprising, receiving a radar signal reflected from a target on a plurality of antennas, wherein the radar signal is a frequency modulated continuous wave (FMCW) signal comprising plurality of chirps, extracting a plurality of range bins from the radar signal, generating a plurality of reference angles and a plurality of reference velocities from a plurality of reference parameters, determining a plurality of reference weights from the plurality of reference angles and plurality of reference velocities, filtering the radar signal with the filter weights set to equal to the plurality of reference weights.

Abstract: A radio frequency receiver comprises a plurality of receiving antennas providing a plurality of radio frequency (RF) signals, a first set of phase shifters providing a first set of analog beams from a first set of RF signals in the plurality of RF signals, a second set of phase shifters providing second set of analog beams from a second set of RF signals and a digital beamformer providing final set of beams employing the first set of analog beams and the second set of analog beams.

Abstract: According to an aspect of the present invention, a signal processor comprises an N-point phase FFT transformer operative to perform a FFT like transformation according to a first relation Y ? [ k ] = ? n = 0 n = N - 1 ? ? exp [ j ? ? angle ? [ x ? ( n ) ] ] * exp ? [ - j ? ? 2 ? ? ? ? kn N ] , wherein angle [x(n)] representing the phase of the signal x(n). In that, a plurality of butterfly units with each butterfly unit in the plurality of butterfly units comprises an adder, subtractor and a multiplier, wherein the adder, the subtractor and multiplier receive a phase only signals with a signal amplitude less than unity. The butterfly units are arranged in plurality of stages to perform the operation as in the first relation.

Abstract: An antenna system (201) comprising a set of transmitting elements (320A-K) and a set of receiving elements (310A-N) formed on a same or different planar surface (210), an electromagnetic lens (220) to focus electromagnetic rays transmitted from the set of transmitting elements (320A-K), a convex secondary antenna (240) operative to reflect the electromagnetic rays and a concave parabolic primary antenna (230) operative to transmit the electromagnetic rays in a first direction such that, the lens, the convex secondary antenna and the concave parabolic primary antenna together provide a transmitting gain in the first direction. The set of transmitting elements are disposed at central area of the planar surface and the set of receiving elements are disposed on the periphery of the central area such that the set of receiving elements occupy larger area on the planar surface compared to the set of transmitting elements.

Abstract: In described examples, a method for detecting voice activity includes: receiving a first input signal containing noise; sampling the first input signal to form noise samples; determining a first value corresponding to the noise samples; subsequently receiving a second input signal; sampling the second input signal to form second signal samples; determining a second value corresponding to the second signal samples; forming a ratio of the second value to the first value; comparing the ratio to a predetermined threshold value; and responsive to the comparing, indicating whether voice activity is detected in the second input signal.

Abstract: A radio frequency receiver comprises a plurality of receiving antennas providing a plurality of radio frequency (RF) signals, a first set of phase shifters providing a first set of analog beams from a first set of RF signals in the plurality of RF signals, a second set of phase shifters providing second set of analog beams from a second set of RF signals and a digital beamformer providing final set of beams employing the first set of analog beams and the second set of analog beams.

Abstract: A method of determining a total delay to a radio frequency (RF) signal caused by a path between a start point and an end point comprising, injecting a plurality of frequency tones at the start point, wherein the frequency tones are of different frequency, receiving the plurality of frequency tones at the end point, measuring a plurality phase differences corresponding to difference of phase between the plurality of frequency tones injected at the start point and the corresponding plurality of the frequency tones received at the end point, and determining a total delay to the RF signal caused by the path from at least more than one of the plurality of phase differences measured. The method further comprises determining a total phase shift to the RF signal from the total delay and a frequency of the RF signal.

Abstract: In described examples, a method for detecting voice activity includes: receiving a first input signal containing noise; sampling the first input signal to form noise samples; determining a first value corresponding to the noise samples; subsequently receiving a second input signal; sampling the second input signal to form second signal samples; determining a second value corresponding to the second signal samples; forming a ratio of the second value to the first value; comparing the ratio to a predetermined threshold value; and responsive to the comparing, indicating whether voice activity is detected in the second input signal.

Abstract: In described examples, a method for detecting voice activity includes: receiving a first input signal containing noise; sampling the first input signal to form noise samples; determining a first value corresponding to the noise samples; subsequently receiving a second input signal; sampling the second input signal to form second signal samples; determining a second value corresponding to the second signal samples; forming a ratio of the second value to the first value; comparing the ratio to a predetermined threshold value; and responsive to the comparing, indicating whether voice activity is detected in the second input signal.

Abstract: An antenna system (201) comprising a set of transmitting elements (320A-K) and a set of receiving elements (310A-N) formed on a same or different planar surface (210), an electromagnetic lens (220) to focus electromagnetic rays transmitted from the set of transmitting elements (320A-K), a convex secondary antenna (240) operative to reflect the electromagnetic rays and a concave parabolic primary antenna (230) operative to transmit the electromagnetic rays in a first direction such that, the lens, the convex secondary antenna and the concave parabolic primary antenna together provide a transmitting gain in the first direction. The set of transmitting elements are disposed at central area of the planar surface and the set of receiving elements are disposed on the periphery of the central area such that the set of receiving elements occupy larger area on the planar surface compared to the set of transmitting elements.

Abstract: According to an aspect of the present invention, a signal processor comprises an N-point phase FFT transformer operative to perform a FFT like transformation according to a first relation Y ? [ k ] = ? n = 0 n = N - 1 ? ? exp [ j ? ? angle ? [ x ? ( n ) ] ] * exp ? [ - j ? ? 2 ? ? ? ? kn N ] , wherein angle [x(n)] representing the phase of the signal x(n). In that, a plurality of butterfly units with each butterfly unit in the plurality of butterfly units comprises an adder, subtractor and a multiplier, wherein the adder, the subtractor and multiplier receive a phase only signals with a signal amplitude less than unity. The butterfly units are arranged in plurality of stages to perform the operation as in the first relation.

Abstract: According to an aspect of the present disclosure, a method comprises computing first set of coefficients of a digital filter providing first filter performance, computing a second set of coefficients from the first set of coefficients, forming a difference digital filter with second set of coefficients to produce a difference filter output and adding a compensation factor to the difference filter output to achieve a second performance identical to the first filter performance. According to another aspect, the second set of coefficients are computed as difference between the successive first set of coefficients such that when the first set of coefficients comprises N number of coefficients, the second set of coefficients comprises N?1 number of coefficients.

Abstract: According to an aspect of the present disclosure, a method comprises computing first set of coefficients of a digital filter providing first filter performance, computing a second set of coefficients from the first set of coefficients, forming a difference digital filter with second set of coefficients to produce a difference filter output and adding a compensation factor to the difference filter output to achieve a second performance identical to the first filter performance. According to another aspect, the second set of coefficients are computed as difference between the successive first set of coefficients such that when the first set of coefficients comprises N number of coefficients, the second set of coefficients comprises N?1 number of coefficients.