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We characterize time and power allocations to optimize the sum-throughput of a Wireless Powered Communication Network (WPCN) with Non-Orthogonal Multiple Access (NOMA). In our setup, an Energy Rich (ER) source broadcasts wireless energy to several devices, which use it to simultaneously transmit data to an Access Point (AP) on the uplink. Differently from most prior works, in this paper we consider...
Hybrid ARQ (HARQ) and link adaptation (LA) are two powerful techniques to improve the data throughput in wireless communication systems. However, when integrated with LA, conventional HARQ does not provide much gain over LA without significantly increasing the number of retransmissions and initial coding rate. In this paper, we explore the feasibility of achieving high throughput by combining HARQ...
Multi-path TCP has recently shown great potential to take advantage of the rich path diversity in data center networks (DCN) to increase transmission throughput. However, the small flows, which take a large fraction of data center traffic, will easily get a timeout when split onto multiple paths. Moreover, the dynamic congestions and node failures in DCN will exacerbate the reorder problem of parallel...
This paper deals with the recently introduced class of Non-Surjective Finite Alphabet Iterative Decoders (NS-FAIDs). First, optimization results for an extended class of regular NS-FAIDs are presented. They reveal different possible trade-offs between decoding performance and hardware implementation efficiency. To validate the promises of optimized NS-FAIDs in terms of hardware implementation benefits,...
Slotted ALOHA (SA) algorithms with Successive Interference Cancellation (SIC) decoding have received significant attention lately due to their ability to dramatically increase the throughput of traditional SA. Motivated by increased density of cellular radio access networks due to the introduction of small cells, and dramatic increase of user density in Machine-to-Machine (M2M) communications, SA...
Combined (soft-hard) method for decoding block turbo-product codes is proposed in the paper. The method allows leveraging advantages of soft input data usage with the speed of hard-decoding procedure. The main peculiarity of the method is rule-based decoding stage. The proposed approach simplifies calculation procedure and reaches better correction ability than hard-decision decoder. Mathematical...
The decoding performance of polar codes strongly depends on the decoding algorithm used, while also the decoder throughput and its latency mainly depend on the decoding algorithm. In this work, we implement the powerful successive cancellation list (SCL) decoder on a GPU and identify the bottlenecks of this algorithm with respect to parallel computing and its difficulties. The inherent serial decoding...
Encoder and decoder implementations of the High Efficiency Video Coding (HEVC) standard have been subject to many optimization approaches since the release in 2013. However, the real-time decoding of high quality and ultra high resolution videos is still a very challenging task. Especially entropy decoding (CABAC) is most often the throughput bottleneck for very high bitrates. Syntax Element Partitioning...
The FSM-SADF model of computation is especially suitable for analysing real-time applications with input-dependent behaviour such as different modes, variable execution times and scalable parallelism. Although FSM-SADF specifies which scenario transitions are possible, it does not specify how and when they are decided at runtime. Multiple actors of a scenario, e.g. video stream header parsing, may...
Spinal codes are a recently proposed capacity-achieving rateless code. While hardware encoding of spinal codes is straightforward, the design of an efficient, high-speed hardware decoder poses significant challenges. We present the first such decoder. By relaxing data dependencies inherent in the classic M-algorithm decoder, we obtain area and throughput competitive with 3GPP turbo codes as well as...
There are many research on hybrid selective-repeat ARQ method. In many previous research purposes have been to maximize a throughput on the number of messages delivered to the user. Important theoretical limits were studied under the condition that a decoding error was very small and neglected. In this research we propose the optimal type-I hybrid selective-repeat ARQ with finite receiver buffer....
This paper presents initial results for a novel 128-antenna massive Multiple-Input, Multiple- Output (MIMO) testbed developed through Bristol Is Open in collaboration with National Instruments and Lund University. We believe that the results presented here validate the adoption of massive MIMO as a key enabling technology for 5G and pave the way for further pragmatic research by the massive MIMO community...
Wireless communication systems use adaptive modulation and coding (AMC) as well as hybrid ARQ (HARQ) to mitigate the effects of time-varying and error-prone channels. In this work, we analyze the benefits of combining HARQ and AMC adopting the throughput as a unique performance measure. The analysis of block-fading channels and error-prone decoders allows us to conclude that i) adding HARQ on top...
In this work, we propose and optimize a new coding strategy designed to enhance the throughput of hybrid ARQ (HARQ) transmissions over i.i.d. block-fading channels where the channel state information (CSI) is unknown at the transmitter. Unlike in the conventional approach, where many blocks are exclusively assigned to carry the HARQ rounds of a single packet, we use a joint coding and the same channel...
The discrete memoryless Z-Channel with a confidential message and a cooperative receiver (DM-ZC-CMCR) is considered. A noiseless one-sided rate-limited cooperation link exists between the two receivers. The secrecy level is measured by the equivocation rate. An outer bound on the secrecy-capacity-region DM-ZC-CMCR is derived. An achievable secrecy-rate region is proposed. The secrecy-sum capacity...
Polar codes are a new class of block codes with an explicit construction that provably achieve the capacity of various communications channels, even with the low-complexity successive-cancellation (SC) decoding algorithm. Yet, the more complex successive-cancellation list (SCL) decoding algorithm is gathering more attention lately as it significantly improves the error-correction performance of short-to...
LDPC block codes (LDPC-BCs) have attracted great interests in recent years by highly parallel computation and good bit-error-rate performance, and one of the decoder implementation issues is high routing complexity. LDPC convolutional codes (LDPC-CCs) not only release routing complexity but also are natural to dynamic length of data frame. Thus, the codes are very suitable for video stream and pre-5G...
This paper proposes a QC-LDPC partial parallel architecture that implements a hard decision message passing algorithm based on Gallager-B decoding. The proposed architecture uses an optimized variable node unit, with adaptive threshold, suitable for irregular LDPC codes. We present implementation results for WiMAX rate 1/2 code for FPGA technology. These indicate a cost reduction of 2.5x in logic,...
Network coding (NC) enables us to mix two or more packets into a single coded packet at relay nodes and improve performances in wireless networks. Intra-session sliding window network coding is used at the source nodes and inter-session network coding is employed at the relay node to combine the recovered source packets of source nodes. In this paper, we investigate the performance of the network-coded...
In spatial information networks (SIN), communication links are suffered by periodic time-varying channel noise because of the periodic motion orbit of the space nodes and planets. Moveover, SIN communications may have a probability to fail at random times, such as severe rain attenuation on Ka-band downlinks, or solar scintillation during the superior/inferior solar conjunction. In this paper, we...
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