Texas Instruments Corporation

Shailesh Joshi

Karthik Subburaj

Karthik Ramasubramanian

Indu Prathapan

Dheeraj Kumar Shetty

Vashishth Dudhia

Shankar Narayanamoorthy

Anand Gadiyar

Kameswaran Vengattaramane

Rittu Kulwant Sachdev

Karan Singh Bhatia

Pranav Sinha

Shankar Ram Narayana Moorthy

Piyush Soni

Mayank Kumar Singh

Systems and instruction carrying non-transitory processor-readable mediums are provided to facilitate access of radar data that may be scattered or non-uniformly located within a region of memory for further processing of such radar data. An example system includes counters that increment on different dimensions of the memory region, a lookup table, multipliers, an adder, and a wraparound mechanism to access different sets of non-contiguously stored radar data from a region of memory. The wraparound mechanism performs a wraparound operation when a combined address, generated by the adder based on addresses obtained by the multipliers, is greater than a last valid address in the region. The wraparound operation generates a new combined address that is used to fetch data from the memory. A transform operation is then performed on the fetched data.

Non-uniform multi-dimensional data access for radar data processing

A device includes a comparison circuit and a calculation circuit coupled to the comparison circuit. The comparison circuit is configured to receive a first digital input value (X) and a second digital input value (Y), and provide a first digital output value that indicates one of a first relationship, a second relationship, and a third relationship between X and Y. The calculation circuit is configured to receive X and Y, receive the first digital output value, and provide a second digital output value. The second digital output value is a first linear combination of X and Y responsive to the first digital output value indicating the first relationship, a second linear combination of X and Y responsive to the first digital output value indicating the second relationship, and a third linear combination of X and Y responsive to the first digital output value indicating the third relationship.

Linear approximation of a complex number magnitude

Methods, apparatus, systems and articles of manufacture to compensate radar system calibration are disclosed. A radio-frequency (RF) subsystem having a transmit channel, a receive channel, and a loopback path comprising at least a portion of the transmit channel and at least a portion of the receive channel, a loopback measurer to measure a first loopback response of the RF subsystem for a first calibration configuration of the RF subsystem, and to measure a second loopback response of the RF subsystem for a second calibration configuration of the RF subsystem, and a compensator to adjust at least one of a transmit programmable shifter or a digital front end based on a difference between the first loopback response and the second loopback response to compensate for a loopback response change when the RF subsystem is changed from the first calibration configuration to the second calibration configuration.

Methods and apparatus to compensate for radar system calibration changes

An example radar device includes an antenna system, a transmitter having an input, and an output coupled to an input of the antenna system, the transmitter having modulation circuitry to provide frequency modulated continuous wave (FMCW) signals for transmission by the antenna system; a receive signal processing chain; and a digital front-end. The receive signal processing chain includes an input coupled to an output of the antenna system, and is configured to receive radar reflection signals, process the radar reflected signals to generate an intermediate frequency (IF) baseband signal, and digitize the IF baseband signal to generate digital samples of the IF baseband signal. The digital front-end has an input to receive the digital samples of the IF baseband signal and to phase-shift the digital samples in response to a calibration signal.

Cascaded radar system calibration of baseband imbalances

A device comprises a digital ramp generator, an oscillator, a power amplifier, a low-noise amplifier (LNA), a mixer, and an intermediate frequency amplifier (IFA). The oscillator generates a chirp signal based on an output from the digital ramp generator. The power amplifier receives the chirp signal and outputs an amplified chirp signal to a transmitter antenna. The LNA receives a reflected chirp signal from a receiver antenna. The mixer receives output of the LNA and combines it with the chirp signal from the oscillator. The IFA receives the mixer output signal and includes a configurable high-pass filter, which has a first cutoff frequency during a first portion of the chirp signal and a second cutoff frequency during a second portion of the chirp signal. In some implementations, the first cutoff frequency is chosen based on a frequency of a blocker signal introduced by couplings between the transmitter and receiver antennas.

Intermediate frequency amplifier with a configurable high-pass filter

A system includes a memory configured to store a two-dimensional data structure that includes radar data arranged such that radar data of a first transmitter is separated from radar data of a second transmitter by a Doppler offset in the two-dimensional data structure. The system also includes a data fetch mechanism that includes a lookup table (LUT) applied on either of two dimensions. The lookup table is configured to store a data fetch location in the two-dimensional data structure, where the data fetch location indicates a location from which to fetch a subset of the radar data from the two-dimensional data structure and the data fetch mechanism is configured to fetch the subset of the radar data from the two-dimensional data structure based on the LUT. The system includes a processor configured to perform a fast Fourier transform (FFT) on the fetched subset of the radar data.

A non-transitory computer-readable storage device stores machine instructions which, when executed by a processor, cause the processor to determine a chirp period Tc for radar chirps in a radar frame. The chirp period Tc comprises a rising period Trise and a falling period Tfall. The processor determines, for each radar chirp in the radar frame, a corresponding randomized frequency characteristic during Tfall, and causes a radar sensor circuit to generate the radar chirps in the radar frame based on Tc, Trise, Tfall, and the corresponding randomized frequency characteristics. In some implementations, the machine instructions to determine the corresponding randomized frequency characteristic comprise machine instructions to determine a frequency step having a frequency f_step and a period Tstep. At least one of the frequency f_step and the period Tstep is dithered across radar chirps in the radar frame.

Non-active chirp dithering in FMCW radar

A method for calibrating a cascaded radar system includes transmitting first radar transmission signal from a radar device. First radar reflection signals corresponding to the respective first radar transmission signal reflected from calibration target are received at each of the radar devices. The first radar reflection signals are demodulated to generate first baseband signals at each of the radar devices. A second radar transmission signal is modulated with respect to the first radar transmission signal at the respective one of the radar devices. The second radar transmission signal is transmitted from the respective one of the radar devices and are received as second radar reflection signals at each of the radar devices. The second radar reflection signals are demodulated to generate second baseband signals at each of the radar devices, and each of the radar devices are calibrated based on the first and second baseband signals.

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Bengaluru, India

Shailesh Joshi