In spite of several advantages of free space optics (FSO) such as huge bandwidth, license-free communication and high electromagnetic interference, immunity over radio frequency technology, these systems are also seve...
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ISBN:
(纸本)9781538611449
In spite of several advantages of free space optics (FSO) such as huge bandwidth, license-free communication and high electromagnetic interference, immunity over radio frequency technology, these systems are also severely affected by fog and atmospheric turbulence. Generally, the performance of such communication systems can he measured by the two important parameters such as bit error rate (BER) and Q-factor. To improve the average BER performance of the system various advanced modulation techniques with different coding schemes have been proposed in the past literature. Thus in the proposed system, Manchester coding technique is used with the differential phase shift keying (DPSK) modulated signal. The designed system is compared with the differential phase shift keying with the 2-array pulse position modulation (DPSK-2PPM) scheme and the conventional DPSK system. Manchester encoding synchronizes the signal itself;hence, it minimizes the error rate and optimizes the reliability of the proposed system. In addition, a 16-channel wavelength division multiplexing (WDM) FSO system is considered for improving the spectral efficiency of the system. For analyzing, the low to high turbulence level of atmosphere, Gamma-Gamma type channel model is preferred.
The paper describes experiments that investigated the use of auditory stimuli (speech and non-speech sound) to communicate data in two information systems. These experiments were performed under a multimedia stock con...
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ISBN:
(纸本)0769515061;076951507X
The paper describes experiments that investigated the use of auditory stimuli (speech and non-speech sound) to communicate data in two information systems. These experiments were performed under a multimedia stock control system and a multimedia e-mail tool. Experiments using the multimedia stock control information system investigated rhythms and timbre to communicate windows and their associated junctions as well as the simultaneous use of speech and sound to communicate a large amount of information to users.. Experiments using the multimedia e-mail tool investigated the use of tunes and short pitch sequences with visual stimuli to communicate information in browsing e-mail data. The paper also integrates experimental results from both systems and discusses the incorporation of auditory stimuli in interactive audio-visual or multimedia information systems. Auditory stimuli helped to communicate, complement or re-enforce information that users received via the visual channel. These auditory technologies could also benefit visually impaired users of such systems. Results also indicated that the simultaneous use of sound and speech can be useful in the design of interactive multimedia information systems. The inclusion of auditory stimuli (including speech) in the design of information systems has the potential to maximise the volume of information communicated to users. A set of empirically derived design guidelines for the auditory design of information systems are described. These guidelines include issues of presentation, classification and structure of auditory messages as part of the interface design in interactive or multimedia information systems.
This paper proposes a novel adaptive interpolation filter (AIF) to reduce computational complexity and bit-rate of video coding. In the proposed AIF, the filter coefficients of B frames, which are predicted from those...
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In recent past, researchers have suggested the idea of extending information theory to the microfluidic domain. Along this stream, a few solutions have been proposed to support logic and computing functions as well as...
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ISBN:
(纸本)9781467364324
In recent past, researchers have suggested the idea of extending information theory to the microfluidic domain. Along this stream, a few solutions have been proposed to support logic and computing functions as well as simple communications in droplet-based microfluidic systems. Of course, pursuing this objective, requires a deep knowledge of microfluidic basics and relies on the use of an appropriate informationcoding strategy. Accordingly, in this paper we introduce a possible scheme for informationcoding in microfluidic devices, evaluate its performance by means of some preliminary experimental results and draw a number of considerations.
When the UAV technology meets the multiple-input-multiple-output communications, the precoders for transmission need to fertilize the benefits of high-probability lineof-sight propagation paths. This work investigates...
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ISBN:
(纸本)9780738113456
When the UAV technology meets the multiple-input-multiple-output communications, the precoders for transmission need to fertilize the benefits of high-probability lineof-sight propagation paths. This work investigates the joint design of uplink/downlink precoders for single-cell UAV-mounted wireless systems. While the UAV has finite cruising endurance, the UAV-mounted base transceiver station can scavenge energy from wireless signals in the uplink period, and the deliver useful information to terrestrial users in the downlink period. By exploit the information-theoretical uplink-downlink duality, the weighted throughput can be maximized based on the tailored dirty paper coding scheme. Numerical results are used to demonstrated the effectiveness of the proposed algorithm.
Distributed Video coding (DVC) is a new compression paradigm in video coding, which is receiving lots of interests nowadays. Side information creation is a key function in the DVC decoder, and plays a key-role in dete...
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ISBN:
(纸本)9781424455379
Distributed Video coding (DVC) is a new compression paradigm in video coding, which is receiving lots of interests nowadays. Side information creation is a key function in the DVC decoder, and plays a key-role in determining the performance of the codec. This paper proposes a novel framework to create side information at the block level with two modes: Wyner-Ziv mode and Intra/ WZ mode, corresponding to Motion Compensated Frame Interpolation and motion compensated quality enhancement technique, respectively. While in the second mode, a low quality Intra block sent by the encoder is used to generate side information by doing motion estimation with the help of the reference frames. Experimental results demonstrate that the proposed scheme can achieve up to 2.1dB improvement in rate-distortion performance when compared to state-of-the-art DVC codec, especially for high motion video sequences and long group of pictures sizes.
In this paper, the authors propose a confidence-based joint orthogonal coding and modulation algorithm for soft information cooperation in the time-division broadcast bidirectional relaying networks. We first compute ...
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ISBN:
(纸本)9781424462520
In this paper, the authors propose a confidence-based joint orthogonal coding and modulation algorithm for soft information cooperation in the time-division broadcast bidirectional relaying networks. We first compute the log-likelihood ratio (LLR) of the received signals at relay nodes in the first two time slots, then derive the probability distribution of the scaled LLR. Inspired by the space-time coding, the quadrature components of the orthogonal coded signal is composed by the soft information from two terminals. Later, to reduce the computation complexity of the traditional cluster partition, we quantize the orthogonal coded signal to the lattice points, and propose a confidence-based cluster partition algorithm which is adaptive to the modulation scheme and bandwidth limitation. Moreover, we derive the bit error rate (BER) expression for the proposed algorithm. From the simulation results, it is shown that with multiple relays assisting the transmission, the proposed scheme is outperforms AF, DF and CF strategies in BER metric;while for single relay case, the BER performance of the proposed scheme is comparable with AF, DF and CF strategies.
Network coding is an emergent promising technique that can be used to significantly enhance reliability in wireless multicast networks . In network coding schemes, information is partitioned into a number of blocks, w...
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Power management is the key issue in the design and operation of wireless network applications like sensor networks, pervasive computing and ubiquitous computing where the network is primarily driven by battery-powere...
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ISBN:
(纸本)9788184244397
Power management is the key issue in the design and operation of wireless network applications like sensor networks, pervasive computing and ubiquitous computing where the network is primarily driven by battery-powered embedded devices. This paper studies network coding as power minimization technique. Network coding is a new research area that may have interesting applications in practical networking systems. With network coding, intermediate nodes may send out packets that are linear combinations of previously received information. Thus network coding reduces the power consumption by minimizing the number of transmissions required to communicate a given amount of information across the network. Hence it improves the lifetime of the network when network coding is being applied. This paper explains what is network coding and the benefits of network coding. Evaluation results indicate that the proposed solution is more efficient than no-network coding solution while still meeting the required lifetime constraints.
In this paper, we analysis the error performance improvement of the FS MC-CDMA, whose information data are spread spectrum with direct sequences(DS), and each subband signal is transmitted using a subcarrier frequency...
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ISBN:
(纸本)9780769530062
In this paper, we analysis the error performance improvement of the FS MC-CDMA, whose information data are spread spectrum with direct sequences(DS), and each subband signal is transmitted using a subcarrier frequency, combining BCH code in Mobile communication channels which is characterized by Nakagami fading. The effect of cochannel interference on the block error performance is also studied in this paper. As a results of study, the coding techniques provides more efficient improvement than non-coding, but the coding techniques are required more band as many coding rate. Our study demonstrates that the system is combined coding techniques, the amout of improvement is capable of efficiently exploiting over the Nakagami fading.
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