The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We investigate adaptive transmission for tactical packet radio networks in which a source uses fountain coding to multicast a file to a number of destinations over time-varying links. We examine two strategies from the literature for packet-by-packet adaptation of the modulation and channel code. The maximum data-recovery rate philosophy attempts to maximize the throughput for each transmitted packet...
NarrowBand Waveforms (NBWF) are often used in VHF or UHF tactical communications. For these kinds of waveforms, low latency and robust data rates result in short codeword lengths that are challenging in terms of channel coding. Usually, serially concatenated convolutional code and continuous phase modulation (CC-CPM) schemes are considered in the context of NBWF. When evaluating the achievable rates,...
A parameter optimization scheme of block interleaver for polar coding with bit-interleaved coded modulation (BICM) is proposed in this paper. We analyze the characteristics of a random interleaver applied to polar codes with high-order modulation, which is ideal but infeasible to implement. Then we derive the parameter optimization algorithm of block interleaver for polar coding with BICM. The block...
Unmanned aerial vehicles (UAVs) are widely used in military due to the hostile environment and safety concern. To tackle the challenges on UAV communications, millimeter wave (MMwave) communication has been considered as a potential solution for both security and high throughput capability. However, insufficient research has been carried out for MMwave communications on drone, and no widely recognized...
Telehaptic systems aim at providing a higher level of immersion into a remote environment by adding an ability of physical interaction with the objects and/or people in the distant space. A system consists of an operator and a remote robotic device equipped with sensors and actuators which can transmit interaction parameters to the operator upon the contact with the environment. Telehaptic systems...
4G Long Term Evolution (LTE) mobile system adopts Adaptive Modulation and Coding (AMC) as a link adaption mechanism that is based on the User Equipment (UE) periodically reporting channel condition summarised through Channel Quality Indicator (CQI) which, in turn, is based on Signal-to-Interference-plus-Noise Ratio (SINR) and Reference Signal Received Power (RSRP). Although CQI has a predominant role...
In this paper, a high speed digital excess loop delay (ELD) compensation scheme with hybrid thermometer coding is proposed. In this high speed compensation, the time constraint of the DAC feedback route is shifted to the one clock compensation path. Also, the method to deal with the signal overflows the quantizer's range is analyzed. Compared to other digital ELD compensations, this scheme features...
As in-line interference between geostationary(GEO) and Non-Geostationary(NGEO) systems is becoming more and more serious. We propose an efficient utilisation of the adaptive modulation and coding (AMC) scheme for spectral coexistence of GEO and NGEO satellites to mitigate in-line interference. Results of Simulation show that the proposed scheme can improve the performance of the NGEO system in comparison...
Novel technologies based on pulse amplitude modulation (PAM) are studied for a high-speed visible light communication (VLC) system. In this paper, we summarize the latest progress on high-speed PAM-VLC systems including phase shifted Manchester coding, Nyquist filter, weighted pre-equalization, multi-band access, and hybrid time-frequency domain equalization, which supporting VLC high data-rate and...
Chaos-based coded modulation (CCM) systems have been shown to be competitive against important wireless channels impairments, like fading. Nonetheless, these systems have not been tested yet in a real-world scenario, and their performance has only been explored using theoretical and numerical bounds, and validated by simulation. In this proposal, we take advantage of the availability of Software-Defined...
In this invited paper, we describe a rate-adaptive FEC scheme based on LDPC codes together with its software reconfigurable unified FPGA architecture. By FPGA emulation, we demonstrate that this class of rate-adaptive LDPC codes based on shortening with an overhead from 25% to 42.9% provides a coding gain ranging from 13.08 dB to 14.28 dB at a post-FEC BER of 10−15 for BPSK transmission. In addition,...
In digital fringe projection (DFP) techniques, invalid points such as shadows and background cause ambiguity to the measurement. Manually segmenting the object and invalid points is time-wasting, and the improper selection of threshold makes errors in the measurement. In this paper, we propose an automatic threshold selection technique based on both modulation histogram and intensity histogram, which...
In this paper, we mainly focus on the optimization of multi-level coded modulation scheme in terms of sub-channel code rate optimal assignment and irregular QC-LDPC code construction with the aid of EXIT chart analysis. Simulation results show that the proposed MLCM scheme can achieve additional 0.1dB NCG compared with the UEP coded modulation scheme.
Sub-carrier Index modulated OFDM is an innovative technique that has recently gained popularity in the area of visible light communication. The technique is meritorious in that it offers a better BER performance than conventional OFDM, but it still suffers from high CCDF of PAPR distribution as in conventional case. In this paper an experimental study for a novel method of SIM OFDM modified with selective...
Noise robustness has long garnered much interest from researchers and practitioners of the automatic speech recognition (ASR) community due to its paramount importance to the success of ASR systems. This paper presents a novel approach to improving the noise robustness of speech features, building on top of the dictionary learning paradigm. To this end, we employ the K-SVD method and its variants...
Efficient resource utilization with a satisfying quality of service is the key to high capacity in flexible optical networks. In our work, this is achieved by supporting the resource allocation with the Gaussian noise model, which estimates the nonlinear physical-layer impairments. The study includes variable launch power, modulation formats, error-correcting code rates, and various new network features...
Orthogonal frequency division multiplexing with index modulation (OFDM-IM) is a newly proposed technique, which achieves significantly improved performance in comparison with classical OFDM by using the indices of active subcarriers to carry additional information bits. In this paper, we propose two power allocation (PA) algorithms for the sake of further improving the bit error rate (BER) performance...
With the development of high-speed trains (HST), efficient and reliable communication services in high mobility scenarios have become an urgent demand. As one of the strong candidates in 5G wireless system, polar codes along with its optimized design should also be investigated under high mobility scenarios. In this paper, a scheme of hash-concatenated polar codes is proposed to reduce the false alarm...
This paper shows the optimality of Pulse-Position Modulation (PPM) for covert communications over discrete-memoryless channels. Specifically, the concatenation of a random m-ary outer code of length O(m) and an inner code consisting of PPM of order m achieves the information-theoretic limits of covert communications. This suggests alternative code constructions for covert communications, in which...
Using an algebraic approach, we examine the design and the performance of geometrically uniform line coding schemes transmitting b bits over w = b + 1 wires and obtained from a subset of a permutation modulation signal set.
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.