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We propose a simple yet effective wireless network coding (NC) and decoding technique. It utilizes spatial diversity through cooperation between nodes which carry out distributed encoding operations dictated by generator matrices of linear block codes. For this purpose, we make use of greedy codes over the binary field and show that desired diversity orders can be flexibly assigned to nodes in a multiple...
In this paper, we investigate different HARQ strategies with unreliable feedback channel. In classical approaches, retransmitted packets are different versions of the same user data. In order to improve HARQ performance, we propose to construct redundancy packets by jointly encoding several data packets. This strategy is referred to as HARQ Multiple Packet Incremental Redundancy (MP-IR). It can eliminate...
This paper presents two new techniques employing bandwidth-efficient modulation to enable two partners to cooperatively convey their data to a common destination. Both approaches integrate relaying and channel coding, exploiting the fact that each partner knows the data relayed by the other partner to enhance the partner-to-partner link. The first approach is based on bit-interleaved coded modulation...
To date there is no practical means to evaluate the true word error probability (WEP) of a given turbo or LDPC code because typical decoders cannot achieve the performance of ML decoding. In this paper, we propose a viable methodology to establish tight bounds on the ML-decoding WEP for these codes through empirical simulation. Our framework centers on the efficient use of multiple-output decoding...
In this paper we analyze the performance of several bit-interleaving strategies applied to Non-Binary Low-Density Parity-Check (LDPC) codes over the Rayleigh fading channel. The technique of bit-interleaving used over fading channel introduces diversity which could provide important gains in terms of frame error probability and detection. This paper demonstrates the importance of the way of implementing...
As part of the tradeoff between error performance, decoding complexity and the overhead of rateless codes, the combination of incremental decoding (ID) and informed dynamic scheduling (IDS), known as IDIDS (incremental decoding with informed dynamic scheduling), is an attractive solution in binary symmetric channels (BSC). However, applying IDIDS in the AWGN (additive white Gaussian noise) channel...
A new space-time block code (STBC) is presented for distributed 4 × 2 multiple-input multiple-output (MIMO) systems. A 2 × 2 full-rate full-diversity (FR-FD) low complexity space-time code, presented by Sezginer and Sari, is employed for two distributed links. Alamouti STBC is applied over the two links to obtain a double layer space-time block code (DLSTBC) providing full diversity in a distributed...
We propose a packet delayed lattice reduction aided MIMO detection for 802.1 1n system. Lattice reduction algorithms are iterative in nature that results in long latency. In high throughput systems like 802.11n, reduction of latency via parallelization causes high hardware complexity. Without parallelization, the receiver needs to buffer the incoming data until the lattice reduction finishes. Depending...
In this paper, we propose an orthogonal space-time block coding (STBC) for continuous phase modulation (CPM) over frequency-selective channels. The new method maintains the constant envelope and the phase continuity of the CPM waveforms by inserting three blocks of data-dependent symbols in addition to a cyclic prefix (CP). At the transmitter, the data blocks are precoded and transmitted in two antennas...
We consider rate splitting and interference cancelation in Device-to-Device (D2D) communications underlaying a cellular network. We assume that a transmitted message is split into a private and a public part, as in Han-Kobayashi scheme. The private part is decodable only by the intended receiver, whereas the public part is in addition decodable by an interference victim. The receivers run a best-effort...
We study the error and diversity-multiplexing tradeoff (DMT) performance of a (secondary) multi-user relay network, where a class of finite field network codes are applied in the relays to efficiently provide spatial diversity. To eliminate spectral efficiency loss induced by half-duplex limitation we adopt the cognitive radio overlay spectrum sharing concept and consider aligning the relays' operation...
We design a multiple-access relay network with multiple sources and relays via network coded cooperation where the radio resources in three dimensions: time, space and user are jointly optimized. For this, we derive the decoding error probability of two MIMO modes and develop an optimal MIMO mode selection and power allocation strategy for multiple sources and relays, so as to minimize the decoding...
In a multi-cell wireless network, an efficient interference mitigation technique is an inevitable part of the current state-of-the-art wireless system. As opposed to conventional interference mitigation techniques which treat the interference as noise, a multi-layer rate splitting scheme can be considered to improve the performance by decoding part of the interference. In this paper, we adapt the...
Hybrid automatic repeat request (HARQ) is a well-known technique for improving system throughput and link performance of wireless communication systems, including cooperative communication systems. In this paper, we exploit the limited feedback applied to the two-source turbo coded cooperation scheme to define a particular cooperative HARQ protocol, called two-level HARQ, where the decision on retransmission...
This paper investigates the impact of noise dependence and signal delay on the capacities of networks. It is shown that statistical dependence between the noise in a network's component channels is helpful for communication. In particular, the capacity region of a network whose component channels exhibit dependent noise is a superset of the capacity region of a network built from the same component...
Cooperation among nodes is proposed as an effective means of combating fading and for enhancing system's overall capacity and coverage. The robustness of rateless codes makes them particularly attractive for such networks. Yet, the decoding aspects of rateless codes are discarded in most of the traditional distributed networks. In this paper, the intermediate packet decodability of rateless codes...
3GPP long term evolution (LTE) Turbo coded modulation is well-known for its excellent error-control capability. However, its decoding threshold is still a few decibels away from the constellation-constrained capacity. In this paper, an irregular mapping scheme involving labeling search is proposed to improve the performance of the LTE system. The scheme first predetermines one labeling, and then searches...
Recently, Delay-Tolerant Space-Time Codes (DT-STCs) have been designed for cooperative communications. They are optimal in synchronous transmission and preserve their full-diversity order for arbitrary delays in asynchronous case. In this paper, we investigate these DT-STCs in femtocell networks where Femtocell Access Points can assist Macrocell Base Stations to transmit data information to users...
This paper presents a category of detection schemes for Multiple-Input Multiple-Output (MIMO) system called Parallel Sphere Decoder (PSD). Compared to the conventional depth-first sphere decoder with Schnorr-Euchner enumeration (SE-SD), the proposed PSD algorithms use parallel computations and achieve approximately 50% searching time reductions under the same amount of computations. Namely, in hardware...
We present a new 4×4 Hadamard-precoded Quasi-Orthogonal Space-Time Block Code (QO-STBC) that enables reliability-based prioritized symbol detection using linear filters. Approximate block-error-rate analysis is carried out and used to optimize the code rotation angles. For benchmarking purposes, the maximum-likelihood (ML) code detector is also derived with complexity of the order of joint two-real-symbol...
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