Mixed-signal matched filter for high-rate communication systems

2008 ◽  
Vol 2 (4) ◽  
pp. 354 ◽  
Author(s):  
M.R. Zahabi ◽  
V. Meghdadi ◽  
J.P. Cances ◽  
A. Saemi
Keyword(s):  
Communication Systems ◽  
Matched Filter ◽  
High Rate ◽  
Mixed Signal

Effective Multi-Layer Security for Campus Network

2015 ◽  
Vol 2 ◽  
pp. 6
Author(s):  
Isiaka Ajewale Alimi
Keyword(s):  
Network Architecture ◽  
Communication Systems ◽  
Denial Of Service ◽  
High Rate ◽  
Campus Network ◽  
Security Measures ◽  
Security Breaches ◽  
Security Technologies ◽  
Network Layers ◽  
Firewall System

The development in different communication systems as well as multimedia applications and services leads to high rate of Internet usage. However, transmission of information over such networks can be compromised and security breaches such as virus, denial of service, unauthorized access, and theft of proprietary information which may have devastating impact on the system may occur if adequate security measures are not employed. Consequently, building viable, effective, and safe network is one of the main technical challenges of information transmission in campus networks. Furthermore, it has been observed that, network threats and attacks exist from the lower layers of network traffic to the application layer; therefore, this paper proposes an effective multi-layer firewall system for augmenting the functionalities of other network security technologies due to the fact that, irrespective of the type of access control being employed, attacks are still bound to occur. The effectiveness of the proposed network architecture is demonstrated using Cisco Packet Tracer. The simulation results show that, implementation of the proposed topology is viable and offers reasonable degree of security at different network layers.

scholarly journals Low Power Digital Multimedia Telecommunication Designs

VLSI Design ◽  
2001 ◽  
Vol 12 (3) ◽  
pp. 301-315 ◽  
Author(s):  
Koon-Shik Cho ◽  
Jun-Dong Cho
Keyword(s):  
Motion Estimation ◽  
Low Power ◽  
Communication Systems ◽  
Matched Filter ◽  
Optimization Technique ◽  
Low Power Design ◽  
Multimedia Systems ◽  
Wireless Multimedia ◽  
Design Constraint ◽  
Power Capability

The increasing prominence of wireless multimedia systems and the need to limit power capability in very-high density VLSI chips have led to rapid and innovative developments in low-power design. Power reduction has emerged as a significant design constraint in VLSI design. The need for wireless multimedia systems leads to much higher power consumption than traditional portable applications. This paper presents possible optimization technique to reduce the energy consumption for wireless multimedia communication systems. Four topics are presented in the wireless communication systems subsection which deal with architectures such as PN acquisition, parallel correlator, matched filter and channel coding. Two topics include the IDCT and motion estimation in multimedia application.These topics consider algorithms and architectures for low power design such as using hybrid architecture in PN acquisition, analyzing the algorithm and optimizing the sample storage in parallel correlator, using complex matched filter that analog operational circuits controlled by digital signals, adopting bit serial arithmetic for the ACS operation in viterbi decoder, using CRC to adaptively terminate the SOVA iteration in turbo decoder, using codesign in RS codec, disabling the processing elements as soon as the distortion values become great than the minimum distortion value in motion estimation, and exploiting the relative occurrence of zero-valued DCT coefficient in IDCT.

Improving the performance of third-generation wireless communication systems

2004 ◽  
Vol 36 (4) ◽  
pp. 1046-1084 ◽  
Author(s):  
Remco van der Hofstad ◽  
Marten J. Klok
Keyword(s):  
Interference Cancellation ◽  
Communication Systems ◽  
Matched Filter ◽  
Wireless Communication Systems ◽  
Third Generation ◽  
Parallel Interference Cancellation ◽  
Use Of Resources ◽  
Two Parameters ◽  
Code Division Multiple

The third-generation (3G) mobile communication system uses a technique called code division multiple access (CDMA), in which multiple users use the same frequency and time domain. The data signals of the users are distinguished using codes. When there are many users, interference deteriorates the quality of the system. For more efficient use of resources, we wish to allow more users to transmit simultaneously, by using algorithms that utilize the structure of the CDMA system more effectively than the simple matched filter (MF) system used in the proposed 3G systems. In this paper, we investigate an advanced algorithm called hard-decision parallel interference cancellation (HD-PIC), in which estimates of the interfering signals are used to improve the quality of the signal of the desired user. We compare HD-PIC with MF in a simple case, where the only two parameters are the number of users and the length of the coding sequences. We focus on the exponential rate for the probability of a bit-error, explain the relevance of this parameter, and investigate how it scales when the number of users grows large. We also review extensions of our results, proved elsewhere, showing that in HD-PIC, more users can transmit without errors than in the MF system.

scholarly journals On the Feasibility of High Speed Railway mmWave Channels in Tunnel Scenario

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Guangkai Li ◽  
Bo Ai ◽  
Danping He ◽  
Zhangdui Zhong ◽  
Bing Hui ◽  
...  
Keyword(s):  
Millimeter Wave ◽  
Communication Systems ◽  
High Speed ◽  
Radio Channel ◽  
Wide Band ◽  
Directional Antenna ◽  
Propagation Loss ◽  
High Rate ◽  
Railway Tunnel ◽  
High Data

Rail traffic is widely acknowledged as an efficient and green transportation pattern and its evolution attracts a lot of attention. However, the key point of the evolution is how to develop the railway services from traditional handling of the critical signaling applications only to high data rate applications, such as real-time videos for surveillance and entertainments. The promising method is trying to use millimeter wave which includes dozens of GHz bandwidths to bridge the high rate demand and frequency shortage. In this paper, the channel characteristics in an arched railway tunnel are investigated owing to their significance of designing reliable communication systems. Meantime, as millimeter wave suffers from higher propagation loss, directional antenna is widely accepted for designing the communication system. The specific changes that directional antenna brings to the radio channel are studied and compared to the performances of omnidirectional antenna. Note that the study is based on enhanced wide-band ray tracing tool where the electromagnetic and scattering parameters of the main materials of the tunnel are measured and fitted with predicting models.

SILICON-BASED INTEGRATED MOSFETS AND MESFETS: A NEW PARADIGM FOR LOW POWER, MIXED SIGNAL, MONOLITHIC SYSTEMS USING COMMERCIALLY AVAILABLE SOI

2006 ◽  
Vol 16 (02) ◽  
pp. 723-732 ◽  
Author(s):  
JINMAN YANG ◽  
ASHA BALIJEPALLI ◽  
TREVOR J. THORNTON ◽  
JAMES VANDERSAND ◽  
BENJAMIN J. BLALOCK ◽  
...  
Keyword(s):  
Communication Systems ◽  
High Speed ◽  
Field Effect Transistors ◽  
Circuit Simulation ◽  
Drain Current ◽  
Low Noise ◽  
Measured Data ◽  
Silicon On Insulator ◽  
New Paradigm ◽  
Mixed Signal

Metal Semiconductor Field Effect Transistors fabricated using compound semiconductor materials have important applications in high-speed/low-noise communication systems. However, their integration densities are low compared to silicon technologies, and it is difficult to combine them with conventional CMOS for single-chip, mixed-signal circuit applications. In this paper we describe how silicon-on-insulator MESFETs can be fabricated alongside conventional MOSFETs using a commercially available silicon-on-insulator foundry. The process flow for the integrated MOSFETS and MESFETs is presented. Measurements from MESFETs fabricated using a commercial foundry demonstrate good depletion-mode device operation. The measured data confirms a square-law behavior for the saturated drain current, which can be reproduced using readily available MESFET models for Spice circuit simulation. The Spice model is applied to a simple differential-pair amplifier and the modeled results compared to measured data.

Serially concatenated space-time code (SCSTC) for high rate wireless communication systems

2000 ◽  
Vol 36 (7) ◽  
pp. 646 ◽  
Author(s):  
Woong-Gon Kim ◽  
Bon-Jin Ku ◽  
Lee-Hyun Baek ◽  
Ha-Young Yang ◽  
Chang-Eon Kang
Keyword(s):  
Wireless Communication ◽  
Communication Systems ◽  
Space Time ◽  
High Rate ◽  
Wireless Communication Systems ◽  
Time Code ◽  
Serially Concatenated

scholarly journals Information-Bottleneck Decoding of High-Rate Irregular LDPC Codes for Optical Communication Using Message Alignment

2018 ◽  
Vol 8 (10) ◽  
pp. 1884 ◽  
Author(s):  
Maximilian Stark ◽  
Jan Lewandowsky ◽  
Gerhard Bauch
Keyword(s):  
High Precision ◽  
Optical Communication ◽  
Message Passing ◽  
Communication Systems ◽  
Belief Propagation ◽  
Ldpc Codes ◽  
High Rate ◽  
Double Precision ◽  
Information Bottleneck ◽  
Irregular Ldpc Codes

In high-throughput applications, low-complexity and low-latency channel decoders are inevitable. Hence, for low-density parity-check (LDPC) codes, message passing decoding has to be implemented with coarse quantization—that is, the exchanged beliefs are quantized with a small number of bits. This can result in a significant performance degradation with respect to decoding with high-precision messages. Recently, so-called information-bottleneck decoders were proposed which leverage a machine learning framework (i.e., the information bottleneck method) to design coarse-precision decoders with error-correction performance close to high-precision belief-propagation decoding. In these decoders, all conventional arithmetic operations are replaced by look-up operations. Irregular LDPC codes for next-generation fiber optical communication systems are characterized by high code rates and large maximum node degrees. Consequently, the implementation complexity is mainly influenced by the memory required to store the look-up tables. In this paper, we show that the complexity of information-bottleneck decoders remains manageable for irregular LDPC codes if our proposed construction approach is deployed. Furthermore, we reveal that in order to design information bottleneck decoders for arbitrary degree distributions, an intermediate construction step which we call message alignment has to be included. Exemplary numerical simulations show that incorporating message alignment in the construction yields a 4-bit information bottleneck decoder which performs only 0.15 dB worse than a double-precision belief propagation decoder and outperforms a min-sum decoder.

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