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We propose a modulation assisted preprocessing scheme to reduce the computational complexity of non-binary LDPC decoding. With the proposed scheme, the received signal is directly mapped onto a truncated symbol vector through table lookup. The mapping table can be built off-line based on the characteristics of the constellation structure. The receiver needs only to calculate and, if necessary, rank...
This paper is concerned with the coded orthogonal frequency division multiplexing (OFDM) with index modulation (IM) for highly mobile wireless communication based on block Markov superposition transmission (BMST). In the OFDM-IM scheme, the information bits are not only mapped into the conventional two-dimensional signal points but also into the indices of the subcarriers. For the coded IM system,...
Differential pulse-position modulation (DPPM) shows significant power and bandwidth efficiency in wireless optical communications and does not need symbol synchronization, but suffers from serious insertion/deletion errors if the low-complexity symbol-by-symbol detection is used. In this paper, the DPPM transmission scheme combining the watermark with the low-density parity-check (LDPC) code is proposed...
We describe a new approach to improve the success rate of symbol decoding with very high-order modulations at receivers equipped with low-resolution analog-to-digital converters (ADC). The proposed method is based on generating self-inflicting pseudo-random white noise signal at the receiving antenna array in order to improve the performance of spatial oversampling. As the optimal amount of this artificially...
This paper presents a link quality model for a wireless communication system with distributed turbo coding and lossy forwarding. The model maps the signal-to-interference-plus-noise ratio (SINR) of packet copies received from different links to a mutual information parameter and, in a second stage, converts it to a block error rate. We present the design and foundation of the model and validate its...
In this paper, we focus on the performance imimprovement of the network coding (NC) based hybrid automatic repeat request chase combining (HARQ-CC) scheme. First, considering the joint detection method with the conventional log- likelihood ratio (LLR) calculation, we design the optimal pair of constellation mappings for bit error rate (BER) minimization. Furthermore, we propose a novel remapping-based...
Multi-input multi-output constant envelope modulation (MIMO-CEM) is considered as a promising low power PHY layer design for emerging Internet of Things (IoT) smart devices. MIMO-CEM efficiently overwhelms the high power consumption in MIMO-OFDM transmit signal comes from its high peak-to-average power ratio (PAPR). Despite its high efficiency in reducing the power consumption in the radio frequency...
Besides coping with the increasing demand of broadband services, 5th Generation (5G) radio access technology is expected to support mission critical communication (MCC) services targeting very low latencies. In this paper, we investigate the feasibility of the usage of an early Hybrid Automatic Repeat reQuest (HARQ) feedback for reducing the latency of acknowledged transmissions without disregaring...
As evident from the increasing number of technical studies on machine type communications, Internet of Things (IoT) has become a hot topic. Among all the initiatives attempting to build end-to-end connectivity solutions, the 3rd Generation Partnership Project (3GPP) is actively working on the integration of IoT features into the existing 2G and 4G network specifications. In the framework of the adaptation...
In this work, Automatic-Repeat-Request (ARQ) and Maximal Ratio Combination (MRC), have been jointly exploited to enhance the confidentiality of wireless services requested by a legitimate user (Bob) against an eavesdropper (Eve). The obtained security performance is analyzed using Packet Error Rate (PER), where the exact PER gap between Bob and Eve is determined. PER is proposed as a new practical...
This paper presents some experimental results on both the channel estimation based minimum mean square error Turbo equalizer (CE MMSE-TEQ) and the direct-adaptation turbo equalizer (DA-TEQ) in single-input single-output (SISO) underwater acoustic (UWA) channels. For CE MMSE-TEQ, we compare the soft-decision feedback Turbo equalizer (SDFE), the bidirectional soft-decision feedback Turbo equalizer (Bi-SDFE)...
Wake-up Radio receivers (WuRx) must be energy-efficient for their integration into Wireless Sensor Networks (WSNs). The most energy-hungry component is the address decoding hardware and it is generally powered by the node battery. In this paper, an addressing mechanism is proposed and the decoding process is explained in detail, on the contrary of previous works. This paper also shows the energy reduction...
The performance of multilevel linear block codes is evaluated on Rayleigh fading channel, where the frames are independent from each other and consists of fading coefficients which are constant in a particular frame. Linear Block Codes perform up to mark in detecting error and correction problems. If this ability of error detection and correction of the linear block codes is used in a multilevel environment...
Communication systems need for regeneration of consistent information by controlling errors in a noisy environment. This is accomplished by incorporating suitable forward error correcting coding techniques into the system. In this context, Turbo Code (TC) is regarded as one of the high-performance forward error correcting codes whose BER performances tends to the “Shannon limit”. An advanced form...
We investigate the application of network coding to file transfers from a single source to multiple destinations in a two-hop ad hoc relay network that consists of half-duplex packet radios. Our network-coded file distribution techniques make simultaneous use of a pair of relay nodes. All transmissions by the source and the relay nodes employ packet-by-packet adaptive modulation and channel coding...
To improve the power-spectral efficiency trade-off of intensity-modulated direct-detection (IM/DD) optical transmissions, enhanced unipolar orthogonal frequency-division multiplexing (eU-OFDM) was recently introduced. Uncoded eU-OFDM systems have been presented in literature but coding techniques to further improve the reliability of transmissions over such systems have not yet been explored. Applying...
In this paper, we study the physical layer abstracting model for MIMO OFDM systems with iterative MMSE receiver. Unlike the abstracting model studied in the literature, we propose to use median variance transfer function to describe the decoder behaviour, where we introduced a new method to compute the symbol variance. The proposed physical layer abstraction model, requires only 2 variance transfer...
In this paper, we study the design of low density signature-orthogonal frequency division multiple access (LDS-OFDM). Compare to the conventional OFDMA system, LDS system has some desirable properties that allows system operating at overloaded conditions. LDS-OFDM system has been shown that outperforms the corresponding OFDMA system. In this paper, we focus on the design of the LDS degrees distribution,...
Avalanche photo-diodes (APD) are widely employed in visible light communication (VLC) systems. Experiments show that under official illuminance APD shot noise can not be ignored due to the multiplication process. Under VLC dual-purpose illumination, symbols on different constellation points inevitably experience different levels of noise. In such a signal dependent noise channel, traditional log likely-hood...
The computation of the Log-Likelihood Ratio (LLR) at the channel output may impose great demand of memory and hardware area, especially for high-order modulations. This paper introduces a new approach for the approximation of the LLR in AWGN channels based on the splitting of the original constellation into smaller sectors. Each new sector has a less complex configuration in which it is possible to...
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