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We propose a rate-adaptive error-correction coding framework for transmission over finite-length block-fading channels, with causal channel state information at the transmitter. A dynamic programming optimization approach can be use to obtain the optimal rate adaptation strategy. A suboptimal rate adaptation strategy is developed for sequential random codes. Numerical results show that significant...
In this paper, we propose a physical layer (PHY) caching scheme to exploit cache-assisted dynamic multihopping gain and cache-induced opportunistic CoMP gain in wireless ad hoc networks. In particular, the PHY caching scheme contains a novel PHY transmission mode called the cache-induced dual-layer CoMP which can support homogeneous opportunistic CoMP in wireless adhoc networks and substantially improves...
Cognitive networks rapidly proliferating into all aspects of computing and communication. Some of them are specially designed for the people with specific ability. However, very few are designed with assistance of the people with disability and elderly who need help during networking. The goal of this project is to study network accessibility issues and their impact in such cognitive network design...
A new scheme for error-free transmission is presented which uses optimized combination of adaptive modulation and coding (AMC) and automatic repeat request (ARQ). Using conventional error correction codes with finite length, a limited value of packet error rate (PER) is inevitable. More powerful codes with more extra parity bits results in lower PER, however, at the cost of more transmit power per...
Machine learning based link optimization of wireless communications often relies on past experience, accurate estimation of channel conditions, and theoretical performance models. Typically, theoretical models poorly match given situations, past experiences are limited, and spectrum sensing of noise and channel conditions pose many hurdles. Hence, traditional cognitive radio engines based on genetic...
The Dynamic Compact Control Language (DCCL) provides a flexible and efficient way to marshall object-messages into very small datagrams. It is well suited to transmission over very low throughput links with small maximum transmission units, such as those commonly used in underwater (acoustic modem) and sea-surface (satellite) applications. DCCL provides a interface description language (IDL) and an...
Traditional encryption techniques require packet overhead, produce processing time delay, and suffer from severe quality of service deterioration due to fades and interference in wireless channels. These issues reduce the effective transmission data rate (throughput) considerably in wireless communications, where data rate with limited bandwidth is the main constraint. In this paper, performance evaluation...
Transmission efficiency is an interesting topic for data link layer developers. The overhead of protocols and coding should be reduced to a minimum. This maximizes a link throughput. This is especially important for high-speed networks, where a small degradation of efficiency will degrade the throughput by several Gbps. We describe a redundancy balancing algorithm for an adaptive hybrid automatic...
In this paper two new schemes of systolic multipliers are proposed, one based on Modified Booth encoding and the other is based on the selection of one of the terms 0, X, 2X, 3X where x is the serial input of the multiplier. The proposed multipliers operate with 100% efficiency that is without zero words inserted between successive data. Systolisity and the continuous operation are achieved without...
A novel cross-layer scheduling and stream switching algorithm for content and channel adaptive video streaming over 1xEV-DO (CDMA-HDR), where stream switching is done according to the receiver buffer level is presented. The instantaneous transmission rate to each user is determined by a multi-objective optimized scheduler, maximizing network throughput and individual receiver buffer levels simultaneously,...
It has been recently observed that some information can be extracted from the received signal by the reader when the tag collision happens. Using the radio cross section (RCS) technique one can determine how many tags are backscattering simultaneously. Motivated by this technique we introduce the new notion of singulation code. In a singulation code, any two collection of codewords, of size up to...
One of the prominent candidate of recent technology is OFDM-IDMA (Orthogonal Frequency Division Multiplexing Interleave Division Multiple Access). IDMA (Interleave Division Multiple Access) inherits most of the advantages of CDMA (Code Division Multiple Access). Adaptive Modulation improves the speediness of digital transmission over fading channels. The performance of system with adaptive modulation...
We present some preliminary results from our investigation of two forms of erasure-correction coding, fountain coding and network coding, when they are employed for file transfers in a distributed packet radio network. The radios adapt the modulation and channel coding of the transmitted signals in response to variations in fading on the links of the network. The control information for the adaptive...
It has been recognized that using network coding improves the reliability and throughput of lossy wireless sensor networks (WSNs). Likewise, it is known that using multi-channel networking protocols can dramatically reduce end-to-end latency and improve throughput. However, to date there has been virtually no research as to how to combine these two techniques in a WSN. This paper presents MuCode,...
Device-to-device communication is currently an active research topic in the cellular industry. D2D communication enables two mobile users in vicinity to directly communicate over a dynamically assigned, licensed spectrum without going through the base station. D2D offers tremendous benefits such as increase in spectral and energy efficiency, offload traffic of the base station and reduce transmission...
The simultaneous use of wireless and power line communications (PLC) channels provides a convenient method for increasing the coverage and throughput of indoor networks. In this paper, we compare coding diversity and modulation diversity schemes that both utilize parallel wireless and PLC links. The signal to noise ratio (SNR) values used in this analysis are determined by conducting a series of average...
Computing problems that handle large amounts of data necessitate the use of lossless data compression for efficient storage and transmission. We present numerical results that showcase the advantages of a novel lossless universal data compression algorithm that uses parallel computational units to increase the throughput with minimal degradation in the compression quality. Our approach is to divide...
The Delay/Disruption Tolerant Network (DTN) is characterized with intermittently connectivity and frequent partitions. Due to this, the DTN routing algorithm is very vulnerable to various kinds of malicious attacks. In this paper, combined with many other DTN forwarding approaches, we propose a multi-stage routing forwarding algorithm so as to further improve network throughput. To ensure the security...
Network coding involves in processing several received packets by a relay node for generating a single packet in systematic manner such that the receivers can regenerate the original packets from this packet received from relay node. The network coding techniques show better throughput only under low traffic condition. This work proposes Maximum Flow Min Cut (MF-MC) algorithm which determine the threshold...
This paper investigates the performance of an overloaded multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system with a repetition code. It has been demonstrated that diversity with block coding prevents the performance degradation induced by signal multiplexing. However, the computational complexity of a joint decoding scheme increases exponentially with the...
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