FMCW transceiver wideband sweep nonlinearity software correction

Abstract

Abstract-This paper presents a novel wideband sweep nonlinearity software correction method for a frequency modulated continuous wave (FMCW) transceiver based on the high-order ambiguity function (HAF) and time resampling. By emphasizing the polynomial-phase nature of the FMCW signal, it is shown that the HAF processing algorithm is well suited for estimating the sweep nonlinearity coefficients. The estimated coefficients are used to build a correction function which is applied by resampling the beat signal on each sweep interval. The sweep nonlinearity correction procedure is validated on real data acquired with a low-cost X-band T/R module.

Short-Range Wideband FMCW Radar for Millimetric Displacement Measurements

“…The coefficients of the polynomial-phase signal (PPS) are estimated using the high-order ambiguity function (HAF) [14] on a reference response which can be either a delay line or a high reflectivity target whose propagation delay should be roughly known. Afterwards, with the estimated coefficients, the nonlinearity correction function is built and applied through a time resampling procedure [15].…”

Modulation Linearization Technique for FM/CW SAR Image Processing Using Range Migration

“…which reduces to one error vector, (ε n T), that can be expressed as a modulation error or a sample time error. Time resampling, by interpolation, of each range profile effectively compensates for the phase error for at the cost of computation time [15,16]. Time resampling ratio can be fixed or optimized using phase error and the largest range of interest [17] by the least squares fit at calibration time.…”

“…Some promising solutions to correct single pulse data are time resampling [15,16] and phase resampling [17]. In terms of discrete samples, the phase of the baseband signal is given by Equation (4) above.…”