In this paper, in order to reduce the probability of radar waveform intercepted by passive detection system, time-bandwidth product is increased, and target improved. This paper tackles holographic RF stealth proposes a joint coding based on linear frequency modulation (LFM) waveform. Joint uses complementary codes perform phase-coding, combines codewords optimized genetic algorithm discrete fr...

In this paper we consider physical-layer network coding (PLNC) in OFDM-based two-way relaying systems. Practically, a key impairment for the application of PLNC is the carrier frequency offset (CFO) mismatch between the sources and the relay, which can not be compensated completely in the multiple-access (MA) phase. As this CFO mismatch results in inter-carrier interference (ICI) for OFDM trans...

Various models have been proposed that attribute judgments of frequency of occurrence either to the direct coding of frequency information or to the estimation of frequency from characteristics of memory traces that are not direct frequency codes. We present three experiments that replicate and further explore a phenomenon that is significant in the distinction between direct and indirect model...

This paper proposes novel space-time-frequency (STF) coding for multiantenna orthogonal frequency-division multiplexing (OFDM) transmissions over frequency-selective Rayleigh fading channels. Incorporating subchannel grouping and choosing appropriate system parameters, we first convert our system into a set of group STF (GSTF) systems. This enables simplification of STF coding within each GSTF ...

one of the limitations of orthogonal frequency division multiplexing (ofdm) in many applications is its sensitivity to frequency shifts, errors normally referred to as carrier frequency offset (cfo). although, this small offset is negligible in conventional single carrier communication systems, it is a severe problem in the ofdm systems. because, the carriers in ofdm are inherently closely spac...

ABSTRACT The concept of “modulation frequency” is shown to be a valuable insight into time-frequency transforms for audio coding. A two-dimensional transform, where the second dimension approximately decomposes the audio signal into modulation frequencies, is proposed. This transform, when applied to audio coding, provides high quality at low data rates and adapt gracefully to changes in availa...

We investigate space-frequency block coding for OFDM systems with multiple transmit antennas, where coding is applied in the frequency domain (OFDM carriers) rather than in the time domain (OFDM symbols). In particular we consider Alamouti’s code, which was shown to be the optimum block code for two transmit antennas and time domain coding. We show that the standard decoding algorithm results i...

This chapter presents a new encoding scheme called alternating frequency-directed equal-run-length (AFDER) coding for test data compression. This encoding scheme together with nine-coded compression technique enhance the test data compression ratio. In the first stage, the pre-generated test cubes with unspecified bits are encoded using nine-coded compression scheme. Later, the proposed encodin...

In this paper, we propose a novel coding for long range Brillouin Optical Time Analysis (BOTDA) distributed sensors based on a combination of time and frequency pulses, resulting in an additional coding gain of √2 with respect to traditional intensity-modulated codes. The generation of frequency-chirped pseudo-arbitrary pulses in return-to-zero (RZ) format with a Direct-Digital Synthesizer (DDS...

A new class of image coding algorithms coupling standard scalar quantization of frequency coefficients with tree-structured quantization (related to spatial structures) has attracted wide attention because its good performance appears to confirm the promised efficiencies of hierarchical representation. This paper addresses the problem of how spatial quantization modes and standard scalar quanti...