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 answer the question in the title negatively. More precisely, the FEC limit is invalid for soft decision decoding and low to medium code rates. A better predictor is the generalized mutual information.
For digital terrestrial television broadcasting (DT-TB) systems, orthogonal frequency division multiplexing (OFDM) technique is considered to be an effective method to combat the frequency selective channel cause by multi-path effect. In the single frequency network (SFN) scenario, Alamouti space frequency block coding (SFBC) is introduced to provide spatial diversity gain and improve the link stability...
Next generation wireless systems will need to have higher spectral efficiency as the expected traffic volumes per unit bandwidth and dimension will inevitably grow. As a consequence, it is necessary to design coding schemes with performances close to the theoretical limits, having at the same time high flexibility and low complexity requirements at the receiver. In this paper we start by pointing...
This paper address the problem related to discontinues-transmission (DTX), acknowledgement (ACK), negative- acknowledgement (NACK) detection in 4G wireless communication standards such as LTE/LTE-A. Typically, power estimate of a soft-demapper output is compared with a predefined threshold value to decode an ACK or NACK at the receiver. In some scenarios when received Downlink control channel (PDCCH)...
This paper proposes a rate adaptation strategy based on Spinal codes, a novel rateless codes, in truncated incremental redundancy hybrid ARQ (HARQ) transmission. The information transmission between Satellite or deep space probes and ground receivers is considered. Too many retransmissions, which are caused by error frame, and long distance lead to considerable delay, up to several seconds. The delay...
In this work, a transmission scheme that combines multi-layer multi-rate (MLMR) coding with quasi-orthogonal space-time block coding (QO-STBC) is proposed. Firstly, the proposed QO-STBC codewords set unequal diversity orders for different transmitted spatial data layers. Then, different spatial data layers are protected by different-rate channel codes with the aim of achieving the same post-decoding...
Long Term Evolution (LTE) is a paradigm for mobile communication providing high speed data. The LTE terms provide a framework for enlarged capacity, enhanced spectrum efficiency and coverage as well as condensed latency as compared to the second and third generation wireless networks. Six downlink channels are used by LTE of which three are data bearing channels and the rest are control channels....
Nanonetworking indicates new solutions for many applications in biomedical and industrial fields. In this paper, we examine the diffusion-based molecular communication for information transmission in nano-networks. Design of practical decoders for resource-limited nano-networks requires an understanding the fundamental performance limits of memory-limited decoders. While some existing works in the...
In this paper we investigate multiple access schemes and multi-carrier waveforms in the context of future 5th Generation (5G) wireless communication systems. We compare classical Frequency Division Multiple Access (FDMA) to Interleave-Division Multiple Access (IDMA) on top of two different multicarrier waveforms: Orthogonal Frequency Division Multiplexing (OFDM) and a new approach called Universal...
The physical layer network coding (PNC) technique exploits the broadcast nature of wireless channels to obtain additional transmission efficiency gains. In this paper, the authors first find and prove that: if we rotate the modulation constellations of multiple sources by proper angles, the points of the equivalent superpositioned constellation at the receiver would cluster into clouds, with each...
Achieving higher aggregate data rates for many simultaneous users is considered as a fundamental challenge for the next generation of wireless systems. With low-density spreading (LDS), one could transmit information by overloading, i.e., using more spreading sequences than chips with reasonable implementation complexity. In this paper, we propose an improvement to the conventional LDS technique that...
This paper explores how iterative channel estimation, symbol detection and decoding at the receiver affects the achievable capacity compared with a non-iterative, purely pilots-based scheme. First, a bound is put on the linear minimum mean-square error (LMMSE) estimator of doubly selective radio channels. Subsequently, a bound on the capacity using an LMMSE estimator is found. These bounds take into...
Outage capacity is one of the widely accepted metrics to predict the maximum reliable information rate over fading channel with channel side information (CSI) at the receiver only. This metric is calculated with the assumption that since CSI is not available at the transmitter side, transmission strategies such as rate adjustment cannot be employed to match channel varying to improve the system spectral...
Interference between macro and femtocells is an important issue for the development of CDMA2000 femtocell networks. More specifically, the reverse link signal of a macro User Equipment may generate an unacceptable level of interference at the femto Base Station. To avoid this situation, interference mitigation techniques could be implemented. All the proposed techniques require to know the state of...
This paper proposes a technique for near optimal estimation of doubly selective fast-fading radio channels with low computational cost. The channel is characterized by an autoregressive (AR) model. A Kalman filter combined with a zero phase filter smoother is used to estimate the channel gains using the detected symbols in a turbo equalization and decoding scheme. It is demonstrated that, compared...
This paper proposes a new efficient stopping criterion for bit-interleaved coded modulation with iterative decoding (BICM-ID) system. The new criterion modifies the existing widely used hard-decision-aided (HDA) stopping criterion by adopting the simple scheme and the idea of setting the second maximum iteration numbers (Imax) in accordance with different signal-to-noise ratios (SNRs). We name it...
Multiple description coding (MDC) can be applied for multipath communication to reduce the negative affect of packet loss, and it is composed of three processes: encoding, quantizing, and decoding. Encoding and decoding are well researched in MDC, but there are few researches that focus on the quantization process. Therefore, this paper focuses on the quantization process of MDC. The aim of this paper...
DVB-SH systems rely on hierarchical modulation to insert local content in the complementary ground component. The local content is inserted as a low priority (LP) bit stream, while the global content will be transmitted as a high-priority (HP) bit stream. At the receiver, the standard approach of extracting the local content from the received signal requires to detect the global content first. Henceforth,...
In this paper, we consider a bit interleaved coded modulation (BIC M) scheme over a frequency selective channel. At the receiver, a turbo-detector composed of a maximum a posteriori (MAP) equalizer, and a MAP decoder is used. The channel is supposed to be unknown at the receiver and estimated using pilot symbols. The aim of the paper is to optimize the mapping between the coded bits and the transmitted...
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...
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.