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In this paper, a practical precoder for EST-based modulation to obtain transmit diversity in frequency-selective channel is considered. First, we design the finite impulse response (FIR) filter based matched filter bound (MFB) as precoder at the transmitter. Then the criterion which evaluates the overall performance of EST-based iterative receiver and adjust the length of FIR filter is proposed.
Spread spectrum (SS) modulation is one of the most commonly used methods for data hiding. However, the capacity of SS-based methods is rather limited. To improve the hiding efficiency, this paper presents a method that employs the parallel combinatory spread spectrum (PCSS), in which the hidden data can be transmitted in parallel with a combination of a few pseudo noise sequences. An informed embedding...
Generalized Frequency Division Multiplexing (GFDM) is a recently proposed multicarrier waveform which is being considered as one of the possible candidates for 5G wireless access technology. Key advantages of GFDM are flexibility and low spectral side-lobes which render it the ability of carrier aggregation and reduced adjacent channel interference. However due to its non-orthogonal nature GFDM suffers...
In this paper, we consider a multi-user communication system with dynamically varying interference on block fading channels. We focus on a multi-antenna receiver, single-antenna transmitters, and the case in which the receiver has no knowledge of the channel state information, interference dynamics, and the variance of the additive noise. Pilot-assisted transmission techniques are employed to enable...
We transmit a 28-GBd Nyquist PDM-16QAM channel with WDM-interferers (37.5-GHz grid) over 80-km SSMF spans. Interference noise analysis reveals substantial nonlinear phase noise for PDM-16QAM interferers compared to PDM-4QAM, while Q-penalty is kept small by appropriate CPE.
A broadly applicable perturbation-based approach is demonstrated for estimating the impact of intra-channel fiber nonlinearities on system performance. The estimated performance for DP-QPSK, DP-8QAM, and DP-16QAM exhibits good agreement with both simulation and experimental results.
TH precoding can effectively eliminate the interference between the channels in the MIMO system, improve the reliability of the system. Compared with the linear precoding, the capacity of the system also has a considerable increase. But there are still some problems. In this paper, the traditional TH precoding is improved. The channel matrix H is decomposed by GMD. The SNR of the parallel MIMO sub...
Blind detection of interference modulation order is studied in this paper. Exploiting the additivity property of cumulants for independent variables, we extend the techniques used in source automatic modulation classification to identify the interference modulation order. Using multi- class support vector machines, we show that accurate prediction performance can be achieved via supervised learning...
Transform domain communication system (TDCS) is a multi- carrier cognitive radio (CR) technique which uses cyclic code shift keying (CCSK) for overlay opportunistic spectrum access. Specifically, at any given time, a TDCS system cyclically shifts a fundamental modulation waveform (i.e., a CR sequence satisfying a dynamic spectrum hole constraint) according to specific input data symbol. In practical...
Several techniques such as carrier aggregation (CA) and cognitive radio (CR) have been proposed to achieve high data rates to meet the demand of future wireless communication systems. Those techniques pose a strict adjacent channel interference (ACI) requirement. However, currently employed orthogonal frequency division multiplexing (OFDM) systems suffer from significant spectrum leakage and require...
Our efforts are being made to realize a high speed and high frequency utilization efficiency millimeter-wave band backhaul system for the purpose of applying it to the 5th generation (5G) mobile networks. We propose a fixed wireless access (FWA) system of full duplex radio communication (called the Directional Division Duplex (DDD) system) capable of simultaneous bi-directional communication of the...
The frequency distinguishability of photon pairs was controlled using spectral reshaping via cross phase modulation. A non-classical dip in a Hong-Ou-Mandel quantum interference experiment was observed for the photons with diminished spectral distinguishability.
Transform Domain Communication System (TDCS) has been proposed as a new candidate applied in the cognitive radio (CR) environment since it can avoid existing users or jammers intelligently over a given bandwidth. The TDCS achieves noise-like property and orthogonality characteristic by generating a PR phase vector through a random phase coding processing. In this paper, a new implementation of TDCS...
In this paper the robustness of the receiver architecture of GSM/EDGE modems is experimentally tested. GMSK and 8PSK modulated signals are used to simulate interference sources on adjacent channels. The results can help to fathom the boundaries for future spectrum allocation strategies leading to more efficient utilization of the available spectrum.
The desirable characteristics of ultra-wideband (UWB) technology are challenged by formidable sampling frequency, performance degradation in the presence of multi-user interference, and complexity of the receiver due to the channel estimation process. In this paper, a low-rate-sampling technique is used to implement M-ary multiple access UWB communications, in both the detection and channel estimation...
A new spectroscopic technique that uses a single CW laser and pseudo-noise modulation provides an absorption spectrum having spectral point spacing of 40 MHz over a 2.5 GHz span in a single 1-ms measurement.
Cross Polarization Interference (XPI) is an inevitable problem in the Co-Channel Dual Polarization (CCDP) system. Therefore, a Cross-Polarization Interference Cancellation (XPIC) is necessary for the system. In this paper, we focus on the XPIC method at baseband, of which the main components are adaptive equalization based on Soft Constraint Satisfaction (SCS) algorithm. The attractive feature of...
In dense wireless scenarios, and particularly under high traffic loads, the design of efficient random access protocols is necessary. Some candidate solutions are based on Direct-Sequence Spread Spectrum (DS-SS) combined with a Successive Interference Cancellation (SIC) demodulator, but the performance of these techniques is highly related to the distribution of the users received power. In that context,...
Increasing the spectral efficiency was always the motivation behind the evolution of wireless communication systems. Also, due to the widespread usage of wireless systems, securing the transmitted data rises as a main concern nowadays. Hereby, we introduce a scheme that increases the capacity of wireless systems by transmitting multiple independent data streams, while using the space domain as a source...
We propose a dual-polarization signal-carrier interleaved direct detection (DP-SCI-DD) scheme to achieve 100% spectrum efficiency with reference to single polarization coherent detection. The channel is modeled as a discrete time Gaussian channel with conjugate inter-symbol interference.
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