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Digital Telecommunications, , 2006. ICDT '06. International Conference on

Date 29-31 Aug. 2006

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  • International Conference on Digital Telecommunications - Cover

    Page(s): c1
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  • International Conference on Digital Telecommunications - Title

    Page(s): i - iii
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  • International Conference on Digital Telecommunications - Copyright

    Page(s): iv
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  • International Conference on Digital Telecommunications - Table of contents

    Page(s): v - x
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  • Preface

    Page(s): xi
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  • ICDT Committees

    Page(s): xii
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  • A Data-Flow Platform for Implementing Algorithm-Dependent ASIC Hardware Using Data-Driven Processors

    Page(s): 1
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (254 KB) |  | HTML iconHTML  

    The design details of a new data driven processor (DDP) which simplifies data management and processor hardware is demonstrated. The processor consists of an input port for handling external real-time data, a second input port for exchanging networked inter-processor data, a multi-port RAM, a flag memory, an ALU and a controller. The key benefit of this processor is to be able to handle real-time streaming data through a dedicated port while exchanging data with other processors on a network. Each processor is identical with the exception of the ALU which is custom-tailored for a specific task to simplify processor hardware. Algorithm-dependent wireless communication and multimedia tasks can be implemented using software development on a network of DDPs. This work implements the base-band portion of a simple direct sequence spread spectrum (DSSS) transmitter using a software platform that requires four networked DDP cores. The transmitter design produced one chip for every 15 clock cycles and 225 clock cycles to process one symbol. This resulted in 11 MBit/sec transmission bandwidth which required 825 MHz clock frequency to reach 802.11b WLAN rate View full abstract»

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  • Design of Mobile Receiver in Ultrawideband Impulse Radio System Using Time-Hopping and PPM Modulation

    Page(s): 2
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (231 KB) |  | HTML iconHTML  

    Ultra wideband (UWB) impulse radio (IR) system has recently being considered for several applications due to its attractive features that include low-power carrierless and ample multipath diversity. Among the various modulation and multiple access schemes, this paper deals with time-hopping (TH) binary pulse position modulation (PPM) operating in the presence of frequency-selective multipath fading downlink channel. We develop two types of low-complexity mobile station (MS) receivers. One is based on the RAKE reception scheme and the other is designed to meet the minimum output energy (MOE) criterion. However, since accurate channel information is crucial for reliable operation, thereby we propose a blind (non-data aided) channel estimator. Simulation results show that the MOE receiver outperforms the RAKE receiver in multiuser environment. Moreover, both the channel estimation algorithm and the MOE reception schemes are shown to be reliable and near-far resistant View full abstract»

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  • Data-aided Equalization Scheme for Filtered Multitone Modulation System

    Page(s): 3
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (108 KB) |  | HTML iconHTML  

    Data-aided equalizers are adopted in filtered multitone modulation systems. A new algorithm based on factor graph is proposed in order to combat the non-causality of traditional data-aided equalization scheme. Simulation results show that data-aided equalizers have better performance than decision feedback equalizers View full abstract»

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  • HNN-based Multiuser Receiving for Uplink CDMA Systems

    Page(s): 4
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (115 KB) |  | HTML iconHTML  

    In this paper, novel Hopfield neural network (HNN) technique is proposed for the multiuser receiving of the uplink CDMA system. The proposed receiving scheme resolves the collective effects of both the inter-symbol interference due to the multipath fading channel and the multiple access interference in the multiuser uplink CDMA communication. Simulations demonstrate the effectiveness of the proposed scheme View full abstract»

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  • Notice of Violation of IEEE Publication Principles
    Viterbi Algorithm in Continuous-Phase Frequency Shift Keying

    Page(s): 5
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    Notice of Violation of IEEE Publication Principles

    "Viterbi Algorithm in Continuous-Phase Frequency Shift Keying"
    by Hailun Tan
    in the Proceedings of the International Conference on Digital Communications, 2006 (ICDT'06), August 2006

    After careful and considered review of the content and authorship of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE's Publication Principles.

    This paper is a revised version of the following paper. The lead author, Liang Miao, was not informed of the revisions.

    "Application of Viterbi Algorithm in Binary Continuous Phase FSK"
    by Liang Miao, Hailun Tan
    in a Research Report presented at Australia National University, October 2003

    In this paper, the theory of Viterbi Algorithm is introduced based on convolutional coding. The application of Viterbi Algorithm in the continuous-phase frequency shift keying (CPFSK) is presented. Analysis for the performance is made and compared with the conventional coherent estimator and the complexity of the implementation of the Viterbi decoder in hardware device is analyzed. At last the relevant conclusion is given View full abstract»

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  • Perceptual Acoustic Echo Suppressor for Audio Communication over Packet Networks

    Page(s): 6
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (95 KB) |  | HTML iconHTML  

    This paper presents an acoustic echo suppressor based on spectral subtraction that takes into account the perceptual effects of human hearing. This paper also propose here a method where the echo delay does not increase the computational cost. Effectively, in wireless system, it is not uncommon to have round trip delay up to 300 ms and even more. On most of echo cancellers, increasing the tail length makes the computation to increase. We will propose a method to have fixed computational cost whatever the echo delay is, based on the echo path delay estimation. Also, we will take into account all the perceptual effects (temporal post-masking, perceived echo versus end-to-end delay) that could improve the perceived voice quality View full abstract»

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  • Skip Prediction and Early Termination for Fast Mode Decision in H.264/AVC

    Page(s): 7
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (208 KB) |  | HTML iconHTML  

    his paper proposes a fast mode decision algorithm for H.264/AVC based on skip prediction and early termination techniques. The skip decision is based on a partially computed sum of absolute differences metric combined with utilization of the Lagrangian rate-distortion cost function from the previous frame. A statistical analysis of the spatio-temporal characteristics of the rate distortion cost function and SAD metric for skip decisions is provided. Experimental results show that the new algorithm outperforms existing ones in performance providing a 55% reduction in total computational complexity, a slight reduction in bit rate and negligible impact on visual quality View full abstract»

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  • Spatio-Temporal MIMO Systems for Multiuser Communications under Frequency Selective Fading

    Page(s): 8
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (181 KB) |  | HTML iconHTML  

    This paper presents multiple input multiple output (MIMO) system adopting spatio-temporal processing in both transmitter and receiver sides for multiuser communication under frequency selective fading (FSF). The proposed system assumes the perfect channel state information (CSI) at the base station (BS), and all the weights are computed at BS and then fed back to mobile stations (MSs). The weights of both sides are calculated circularly based on maximum SINR criterion fixing the weights in one side of BS or MS during the optimization of the other side. Computer simulations are carried out to verify the effectiveness and the performance of the proposed scheme View full abstract»

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  • A Novel Channel Estimator Based on Polynomial Fitting Method in PSAM Communication Systems

    Page(s): 9
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (138 KB) |  | HTML iconHTML  

    A novel PF (polynomial fitting) method with great complexity degradation is proposed to get refined channel estimation for the PSAM (pilot symbol assisted modulation) communication systems in this paper. Different from the classical channel estimator based on the linear interpolation of the received pilot signals, the PF-based channel estimator is developed to avoid the repetitious process of the pilot signals. The impact of the polynomial order and fitting length on the channel estimation errors are studied. The Monte-Carlo simulations are also utilized to evaluate the proposed algorithm, and the results show that it is very simple and can achieve good performance over wide range of SNRs (signal-to-noise ratios) and velocities View full abstract»

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  • An Artificial Immune-based Feature Interaction Detection Method

    Page(s): 10
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (157 KB) |  | HTML iconHTML  

    Based on analyzing the similarities of the feature interaction detection system and artificial immune system, an artificial immune-based feature interaction detection method is proposed to detect all kinds of feature interactions in the next generation network, which references the multi-layer protection of the immune system and some immune principles, including the immune recognition, co-stimulation, immune learning, clone selection and self tolerance. The simulation and research show that this method is capable of detecting all kinds of feature interactions neatly, enhancing the detection ratio and efficiency dynamically, and adapting to multi-network with high expansibility and universality View full abstract»

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  • Adaptive Reduced-Rank Interference Suppression for MIMO Decoding

    Page(s): 11
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (176 KB) |  | HTML iconHTML  

    We present an adaptive reduced-rank solution for robust decoding of spatial multiplexed multiple-input multiple-output (MIMO) wireless communications using the multi-stage Wiener filter (MSWF). The huge spectral efficiency gains promised by spatial multiplexing schemes, such as vertical Bell Labs space time (V-BLAST) and space-division multiple access (SDMA), are difficult to realize for less than ideal channel conditions. This is particularly true for military applications where extreme channel conditions such as co-channel interference and intentional jamming can be expected. We show that the MSWF, first proposed by Goldstein and Reed for sensor array application, as combined here with spatial multiplexing decoding method successive interference (SIC) leads to significant signal subspace compression or rank-reduction. As a result our solution converges much faster than full rank methods permitting shorter training length and robustness to co-channel interference and jamming. Also, significant computational reduction is realized making this method a good candidate for portable applications where computational resources are limited. We also present a novel rank-reduction stopping rule which adapts to channel condition. Bit error rate (BER) versus SNR for the correlated channel and for co-channel interference and SINR versus the MSWF rank-reduction and length of training interval are presented View full abstract»

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  • Kids Finder Through Bluetooth Technology

    Page(s): 12
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (203 KB) |  | HTML iconHTML  

    A statistic on children been kidnapped or been lured away by strangers is continuously increased. There is no safer place for kids. For parents or guardians, taking care of their children is not an easy task. Until now, a few wireless or mobile devices based on GPS, Wi-Fi and radio frequency are available in the market enabling the parent to monitor child's whereabouts. Each technology is categorized based on cost, durability and accuracy. However, the usage of Bluetooth is not been explored. Wireless kids finder based on Bluetooth technology can be another good alternative that are cheap and effective. In this paper, the comparison between the proposed Bluetooth based technology with current products and method of detecting are elaborate in detail View full abstract»

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  • A New Rate Control Scheme for H.264/AVC

    Page(s): 13
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (179 KB) |  | HTML iconHTML  

    A novel achievement to optimum bit allocation for H.264/AVC is presented, which is different from JVT-O016 by using a simple linear rate instead of the well-known MPEG-4 Q2 model. To find the global optimum, we resort to Lagrange optimization technique and develop a close-form formula to the optimum problem. It is shown via extensive experiments that the new rate control (RC) scheme exceeds JVT-G012, the current standardized RC scheme and is comparative to JVT-O016 in coding performance View full abstract»

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  • Collaborative Video Annotation Environments: Implemented Features and a new Approach for Object Detection and Recognition

    Page(s): 14
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (437 KB) |  | HTML iconHTML  

    In the different phases of a movie production there is a need for intensive discussion about the produced sequences. Special problems can appear if the discussion members are located at different places and have to describe precisely their critics for the video production. The only possibility to avoid this problem is a meeting that in general involves loss of time and costs. This paper describes an existing approach for a distributed video collaboration tool to simplify and support the video production process for video editing service providers and their customers. The tool is expandable to customer needs by offering a plug-in interface and it is also suitable for just making frame specific annotations. Beside the already existing functions, an object based approach for the video annotation of 3D-modelling-/animation-tools and semi virtual recordings is presented. Based on the standards MPEG-7 and MPEG-4, the collected data can also be passed to other applications View full abstract»

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  • ADAPTIVE PRUNED 4 × 4 DCT ALGORITHM FOR H.264

    Page(s): 15
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (209 KB) |  | HTML iconHTML  

    A new integer 4times4 transform is adopted in the new video coding standard H.264/AVC. To reduce the computation load of the new transform, the SSAVT model for 8times8 transform is applied into H.264 4times4 transform with some modifications. Then, three classes of pruned block are defined and the corresponding simplified butterfly computation processes are designed. Furthermore, a fast DCT algorithm is proposed, with which we can identify the class of pruned block, so as to adopt simplified computation, with the help of modified model for 4times4 transform. Simulation results show that the proposed DCT algorithm saves about average 55% computation of DCT compared with full computation View full abstract»

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  • Fast Motion Estimation using Evolutionary Strategy Search Algorithm

    Page(s): 16
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (247 KB) |  | HTML iconHTML  

    Evolutionary strategy search (ESS) algorithm is a novel method for implementing fast block motion estimation (ME) using evolutionary strategy (ES). It uses a combination of ideas based on existing ME algorithms and employs a novel (1+deltalambda) ES implementation. ESS is essentially a succession of random searches, but by controlling the placement and distribution of these searches in a simple way, it proves possible to achieve comparable motion vector (MV) accuracy to the more established ME algorithms, but with enhanced convergence speed especially for large frame size, high pan and high zoom video sequences View full abstract»

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  • A Fast Coefficients Convertion Method for the Transform Domain MPEG-2 to H.264 Transcoding

    Page(s): 17
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (231 KB) |  | HTML iconHTML  

    Converting MPEG-2 8-tap discrete cosine transform (DCT) coefficients to H.264/AVC 4-tap integer transform (IT) coefficients is one of the indispensable operations for transcoding MPEG-2 to H.264 in the transform domain. Motion information in the input MPEG-2 sequence should be reused as much as possible to speed up the transcoding process. Motivated by this, we first exploits the distribution information of non-zero DCT coefficients to classify the input 8times8 DCT block into three types, then proposes a fast method to perform coefficients conversion based on the type of 8times8 DCT block. The simulation results show that the proposed method significantly reduces the computational complexity, while maintains almost the same video quality compared with the existing method. Hence, it can be efficiently used in the real time transform domain MPEG-2 to H.264 transcoding View full abstract»

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  • Fast Frame/Field Coding for H.264/AVC

    Page(s): 18
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (386 KB) |  | HTML iconHTML  

    Picture-adaptive frame/field (PAFF) coding and macroblock-adaptive frame/field (MBAFF) coding in the new H.264/AVC can improve compression efficiency for interlaced video coding. It is assumed that the optimal solution can be found by employing a multi-pass strategy, which encodes a macroblock or picture with all possible modes and chooses the one with smallest rate-distortion cost, such as the three-pass coding for PAFF and MBAFF coding in reference of H.264/AVC. However, this coding strategy needs high computational complexity. In this paper, a novel single-pass algorithm based on motion activity detection is proposed to predict the mode of PAFF and MBAFF coding in an analysis stage. The simulation results show that the proposed scheme can reduce computational complexity by approximate 60%-75% compared to the three-pass coding method, while maintaining grate coding efficiency View full abstract»

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  • A Simplified Scalable Wavelet Video Codec with MCTF Structure

    Page(s): 19
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1597 KB) |  | HTML iconHTML  

    In recent years, wavelet-based image and video coding systems that utilize a wide range of spatial-temporal-SNR scalability with state-of-the-art coding performance has been proposed in the literature. The strong market acceptance of the new scalable technology stems from advances in network technology as well as various requirements from terminal users since computer network is becoming the main media transmission. This paper presents a simplified scalable wavelet video coding structure using MCTF with 5/3 filter. This structure does not include motion estimation, hence entropy coding for motion vectors is omitted. The proposed codec generates four temporal resolution layers, with up to four spatial resolution levels and six variable quantization levels for certain sequence. Simulation results show the codec has great flexibility feature and the reconstructed video quality is thought to be of acceptable quality View full abstract»

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