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To improve the range and Doppler resolution the bandwidth and the observation time need to be increased. This leads to a range migration effect and thus to a declining separability of targets. This paper compares three different modulation formats to cope with the range migration. The standard chirp-sequence modulation, the bandwidth variation modulation known from literature, and the proposed chirp...
In this paper, we present a flat address space organization called SILC-FM that allows subblocks from two pages to coexist in an interleaved fashion in die-stacked DRAM. Data movement at subblocked granularity consumes less bandwidth compared to migrating the entire large block and prevents fetching useless subblocks that may never get accessed. SILC-FM can get more spatial locality hits than CAMEO...
A 130-GHz OOK transmitter has been developed based on a 65-nm CMOS technology in this work. The transmitter is composed of a 130-GHz fundamental oscillator and a switch-based OOK modulator. The oscillator is based on an LC cross-coupled differential pair with a tapered buffer, while the switch adopts a 3-stage shunt configuration. The on/off power ratio of the switch is over 20 dB, and the transmitter...
To obtain a 20cm-resolution image within a 15m distance using an X-band FMCW radar, an agile chirp frequency synthesizer phase-locked loop (FSPLL) with a wide chirp bandwidth (BW) greater than 750MHz and a short chirp period (Tm) less than 100µs is necessary. Challenges arise as one tries to realize a triangular chirp profile in Fig. 13.1.1 with a fast chirp slope (=BW/Tm) and precise linearity. In...
In this paper, a modulated metasurface structure is introduced for reducing the interference between two dipole antennas placed close to each other in MIMO application. For a system comprising of two dipole antennas of WLAN frequency of 2.4GHz and 6.3GHz respectively, a single metasurface cloak structure covering the 2.4GHz antenna provides proper isolation. The metasurface cloak is patterned with...
In this paper, we propose a frequency coding waveform with a nonlinear frequency modulation (NLFM) signal for the multiple-input multiple-output (MIMO) radar. The transmitted signal of each transmitting antenna is a pulse train, of which, the sub-pulses are NLFM signals with different carrier frequencies. The frequency sequence and the parameter of the nonlinear frequency function are optimized to...
The linearity of the transmitted signal in chirp sequence FMCW radar has a direct impact on the radar baseband, which is used for all target detections and safety functionality. In this paper automotive radar sensors are investigated on the linearity of their transmitted frequency slope. Dominant distortions are analyzed. Results show that distortions can cause peak widening, a wide band SNR degradation...
In order to achieve array gain and spatial diversity or multiplexing gain simultaneously, a novel joint beamforming based on MIMO and array antenna techniques, referred to as J-BF, is proposed for the LTE and Wifi downlink. Array gain is achieved from array antenna based beamforming, referred to as AA-BF. Spatial diversity and multiplexing gains are achieved from MIMO based beamforming, referred to...
This paper discusses the performance of a novel millimeter wave radar sensor for UAS autonomous indoor operations. A sensor based on the interferometric Synthetic Aperture Radar (SAR) principle should be able to satisfy the stringent requirements set by indoor operations in terms of high-resolution three-dimensional mapping and autonomous navigation. A solution based on a Frequency Modulated Continuous...
In military and defense communication systems, frequency hopping technique is considered one of the most effective electronic protective measurements to avoid jamming. Frequency hopping is performed by rapidly changing carrier frequencies during the communication. With the rapid growth of frequency hopped wireless networks, frequency detection and jamming has become a challenging task. In this paper,...
We propose a novel hybrid pulse amplitude modulation single carrier frequency domain equalization (PAM-SC-FDE) system that outperforms similar unipolar systems in terms of bit error rate (BER), bandwidth efficiency, and peak-to-average power ratio (PAPR).
Golay complementary code pairs have the advantage of being biphase, available at a variety of lengths as long as desired, with complete sidelobe cancellation. But, they have the disadvantage of requiring two frequencies/channels with the possibility of inexact sidelobe cancellation due to frequency selective fading. In this paper, the complementary code pair are transmitted at the same frequency band,...
In recent years, multistatic radar systems are extensively used for detection process, as it includes multiple transmitters and multiple receivers spaced at different locations. Due to multiple transmitted signals by multiple transmitters, waveform design with a large time-bandwidth product, low cross-correlation interferences, and a low peak-average power ratio, is a challenging task. Even though...
In this paper, a robust blind extracting audio watermarking scheme based on Improved Spread Spectrum (ISS) and Quadrature Phase Shift Keying (QPSK) is proposed. The frequency of direct spread spectrum sequence signal is reduced to limit its bandwidth, and then modulated to a higher frequency band with QPSK so as to lower the influence of watermarking to listener, meanwhile improve signal-noise ratio...
In this paper, we propose a frequency coding waveform with segment linear frequency modulation (LFM) signal for the multiple-input multiple-output (MIMO) radar. This new waveform is modified from the discrete frequency coding waveform with LFM (DFC-LFM) by changing the subpulse from the LFM signal to segment LFM and extending the contiguous waveform to a pulse train. Compared to the existing frequency...
Phasor measurement unit (PMU) performance depends on the performance of the PMU’s analog input section and the limitations of its DSP algorithms. For the different PMU performance requirements established in the standards, the relative importance of these two factors varies significantly. For steady-state frequency and rate-of-change-of-frequency (ROCOF) measurements, this paper shows that estimation...
We propose and demonstrate a new concept for spectral compression of return-to-zero data streams, based on completely reversible, linear processes, that liberates bandwidth (> 25% of the original signal bandwidth in the reported proof-of-concept experiments) without any loss of information.
MIMO (multiple-input and multiple-output) radar with OFDM (orthogonal frequency-division multiplexing) waveform, i.e., OFDM-MIMO radar, transmits diverse carrier frequency narrowband signals, which can be synthetized to a wideband one to improve the resolution via a method in this paper. We firstly establish the echo model of OFDM-MIMO radar, and then derive the expression of phase compensating factor...
Estimation of the channel distortion characteristics is of crucial importance for realizing a reliable communication. In order to estimate the channel, a received signal is sampled at some rate. The Nyquist rate is widely used notion to determine the sampling rate of the received signal. On the other hand, Vetterli introduced the concept of rate of innovation that is the degree of freedom of the signal...
This paper briefly describe an experimental work which aims at using an acoustic parametric source to detect buried objects. A broadband (150 ~250 kHz) transducer is used as a parametric source and transmitting primary frequency signals with CW and LFM envelope at various pulse lengths and bandwidths. Scattering measurements from a buried metal disk of 15cm diameter is implemented in a...
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