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Polar coding is a low-complexity method for communication over noisy classical channels, which is capable of providing highly reliable data transmission. This paper proposes an enhanced polar codec scheme for mission critical applications in train-to-ground wireless communications. Firstly, we develop an enhanced polar coding scheme to support reliable data transmission under time-varying channel...
In this paper, we investigate the performance of a generic relay system for small cells. The main features include the selection decode-and-forward (DF) scheme, Rician and Rayleigh fading, single or repeated transmissions in direct link, and maximal-ratio combining at destination. We are able to derive a set of closed-form expressions for the end-to-end performance. Based on these formulas, we define...
Polar codes are a family of capacity-achieving error-correcting codes, and they have been selected as part of the next generation wireless communication standard. Each polar code bit-channel is assigned a reliability value, used to determine which bits transmit information and which parity. Relative reliabilities need to be known by both encoders and decoders: in case of multi-mode systems, where...
Efficient code descriptions of rate compatible polar codes are studied. An efficient code description method, so-called the polarization weight sequence that defines multiple codewords, was proposed in 3GPP standardization. We verify the validity of the method for various environments. We assess the performance degradation under successive cancellation (SC) decoding and SC list decoding compared with...
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...
The development of ultrafast ultrasound imaging brings great opportunities to improve imaging technologies such as shear wave elastography and ultrafast Doppler imaging. In ultrafast imaging, there are trade-offs among image signal-to-noise ratio (SNR), resolution, and the high frame rate. Multiplane wave (MW) imaging is proposed to solve this tradeoff by encoding multiple plane waves with positive/negative...
In this paper we consider transmit beamforming schemes for downlink control channel. In particular, we propose exploiting information on user location for selecting both the serving transmission/reception point (TRP) and transmit beam used for control channel transmissions. Moreover, a suppressed zero-forcing (SZF) scheme based on vertically and horizontally polarized transmit beams is proposed with...
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...
Contrast-enhanced ultrasound (CEUS) imaging offers great opportunities for new ultrasound applications by improving the contrast between blood and tissue using microbubbles. However, the low signal-to-noise ratio (SNR) due to the low mechanical index (MI) requirement can sometimes be an issue in practice. Multiplane wave (MW) imaging is a technique recently proposed to increase the SNR for compounding...
We describe a successive cancellation list CRC (Cyclic Redundancy Check)-aided decoder for polar codes over AWGN (Additive White Gaussian Noise) Channel, Fading Channel and Impulsive Noise Channel. Simulation results show the advantage of this decoding method over the original proposed by Arikan.
We define a multiaccess communication scheme that effectively eliminates interference and resolves collisions in many-to-one and many-to-many communication scenarios. Each transmitter is uniquely identified by a coding vector. Using these vectors, all signals issued from a specific transmitter will be aligned along a unique dimension at all receivers hearing this transmission. This dimension is characteristic...
In this work, we show that polar belief propagation (BP) decoding exhibits an error floor behavior which is caused by clipping of the log-likelihood ratios (LLR). The error floor becomes more pronounced for clipping to smaller LLR-values. We introduce a single-value measure quantifying a “relative error floor”, showing, by exhaustive simulations for different lengths, that the error floor is mainly...
The inherent nature of polar codes being channel specific makes it difficult to use them in a setting where the communication channel changes with time. In particular, to be able to use polar codes in a wireless scenario, varying attenuation due to fading needs to be mitigated. To the best of our knowledge, there has been no comprehensive work in this direction thus far. In this work, a practical...
The radio access technology for railway communications is expected to migrate from GSM for Railways (GSM-R) to a more suitable generation of communication systems for the services offered nowadays, like the fourth generation (4G) or the fifth generation (5G). Recently, considerable attention has been devoted to high-speed trains since this particular environment poses challenging problems in terms...
This paper focuses mainly on Bit Error Rate (BER), Signal to Noise Ratio and different Rayleigh channels. We have designed four Rayleigh channels. This paper describes the comparative analysis of different digital modulation techniques like BPSK, QPSK, 8PSK, 16PSK and 16QAM for four Rayleigh channels which are designed. We also compare the convolution coding with different code rates i.e. 1/2, 1/3...
In order to improve the error resistance and security of JPEG2000 standard, a joint source channel and security arithmetic coding/decoding scheme for EBCOT in JPEG2000 is proposed. Based on error resistant arithmetic coding, this scheme inserts multiple forbidden symbols and generates secure two-way decodable bitstream controlled by chaotic maps, improving the security of the scheme. Meanwhile, at...
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,...
We propose the use of differential code shift keying (DCSK) for a symbol rate adaptive low-complexity DSP algorithm by eliminating adaptive-equalizer (AEQ) with limited influence on circuit size. As a proof of concept, a 300km transmission using DCSK format was demonstrated without using AEQ.
The existing algorithms for the selection and switching of signal-code sequences (SCS) in IEEE 802.11 wireless equipment are analyzed. Indicators and criteria for assessing the efficiency of existing SCSs switching algorithms are reviewed. Suggested algorithms for switching SCS are proposed taking into account advantages and disadvantages of such algorithms.
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