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We study the capacity of discrete memoryless channels with synchronization errors and additive noise. We show that with very large alphabets, their capacity can be achieved by i.i.d. input sources, and prove tight lower and upper capacity bounds. An interesting result is that as long as the input sequences are not completely deleted, the capacity of channels with large alphabets corrupted by discrete...
In this paper, we introduce a low overhead scheme for the uplink channel allocation within a single cell of Cognitive Radio Wireless Mesh Network (CR-WMNs). The scheme does not rely on using a Common Control Channel (CCC). The mechanism is based on Physical layer Network Coding (PNC), in which two Secondary Users (SUs) are allowed to transmit synchronously over a randomly selected channel from a set...
A key issue in physical-layer network coding (PNC) is how to deal with the asynchrony between signals transmitted by multiple transmitters. That is, symbols transmitted by different transmitters could arrive at the receiver with symbol misalignment as well as relative carrier-phase offset. In this paper, 1) we propose and investigate a general framework based on belief propagation (BP) that can effectively...
Bayesian recursive inference of phase in additive Gaussian noise environments is studied. A tractable conjugate system is established using a von Mises distribution. Its shaping parameter, κ, is studied, to reveal the link with classical phase estimation via matched transforms. Uncertainty quantifiers involve a modified Bessel function kernel. The optimal predictor of data is derived in the presence...
We have implemented 20,000-word large vocabulary continuous speech recognition (LVCSR) systems employing H- and C-level weighted finite state transducer (WFST) based networks on Graphics Processing Units (GPUs). Both the emission probability computation and the Viterbi beam search are implemented on the GPU in a data-parallel manner to minimize the extra data transfer time between the host CPU and...
In this paper we propose a novel timing and frequency synchronization and decoding method for the P1 symbol in DVB-T2 based on the correlation between the received signal and the time domain P1 symbols. This method does not require post-FFT decoding and is insensitive to the frequency-shift offset and continuous-wave (CW) interference. The performance of the proposed method is evaluated via computer...
Digital audio watermarking has received increasing interest in the last years due to the wide range of applications it can be used for. This contribution presents a novel blind watermarking scheme designed to work in the very specific scenario in which the watermarked audio is played back by a loudspeaker and picked up by the microphone of a mobile device. The proposed scheme is robust against the...
Block-spread code division multiple access (BS-CDMA) systems have been shown to achieve multiuser interference (MUI) free reception when signals of all the users arrive at the base station synchronously. In practice, imperfect timing synchronization destroys the orthogonality among users and MUI occurs. In this paper, based on the fact that unequal interference power distribution occurs in an uplink...
This paper introduces and discusses dependability features of a Telecomm and and Telemetry subsystem designed under a Brazilian Space Program contract. The whole subsystem has been developed in a hardware description language (HDL), targeting anti-fuse programmable once FPGA devices. The discussed features include device redundancy, at hardware level, and several adopted strategies at the HDL level.
Neural control of movement is typically studied in constrained environments where there is a reduced set of possible behaviors. This constraint may unintentionally limit the applicability of findings to the generalized case of unconstrained behavior. We hypothesize that examining the unconstrained state across multiple behavioral contexts will lead to new insights into the neural control of movement...
We propose a system to embed watermark message into audio signal, which can be used for copyright protection. It uses spread spectrum theory to generate a watermark that resistants to different removal attempts. We exploit the psychoacoustic auditory model to guarantee the audio signal's perceptual quality after the watermark embedding procedure. Recovery is performed without knowledge of the original...
Summary form only given. This paper proposes error recovery method for PPM. The proposed method is based on Static PPM, which has partial decoding capability, and divide the source data into blocks. Errors in the block are detected by checking the synchronization symbol which is inserted at the end of each block before compression. Erroneous block is recovered by parity block.
We describe a method to synchronize codeword frames without making use of attached synchronization markers (ASMs). Instead, the synchronizer identifies the code structure present in the received symbols, by operating the decoder for a handful of iterations at each possible symbol offset and forming an appropriate metric. This method is computationally more complex and doesn't perform as well as frame...
Integrated Modular Avionics (IMA) architecture provides means for integrating multiple safety-critical applications on a shared hardware in an airborne system. Error free data transfer between different modules of an IMA cabinet is an issue of critical importance. ARINC 659 has proven to be one of the most comprehensive standards for intra-cabinet data transfer within an IMA cabinet of commercial...
This paper presents the design of a 12-bit 8MSamples/s (MSPS) current-steering digital-to-analog converter (DAC) using 0.13 μm CMOS technology. The proposed DAC has adopted a segmented architecture in order to achieve a minimized die area and optimized performance. The current steering network consists of binary weighted current sources for the 8 least significant bits (LSBs) and a unary current cell...
Free space optical (FSO) communication offers the advantages of compact terminals and very high data rates without using scarce radio frequency spectrum. Unfortunately cloud and fog, together with scintillation caused by small temperature variations in the atmosphere, can result in significant attenuation and highly variable amplitude fluctuations that degrade link availability. This paper describes...
The validation of transaction level models described in System-level Description Languages (SLDLs) often relies on extensive simulation. However, traditional Discrete Event (DE) simulation of SLDLs is cooperative and cannot utilize the available parallelism in modern multi-core CPU hosts. In this work, we study the SLDL execution semantics of concurrent threads and present a multi-core parallel simulation...
This paper discusses the implementation of basic entities for FPGA needed for motor control. Implementation was realized in VHDL (Very-high-speed integrated circuit Hardware Description Language) and was tested with Altera Cyclone II FPGA (Field-programmable gate array). Designed motor control entities have been experimentally verified on developed prototype of an induction motor drive.
Heterogeneous multi-core platforms are widely accepted for high performance multimedia embedded systems. Although pipeline techniques can enhance performance for the multi-core platforms, data dependencies for processing compressed multimedia data makes it difficult, if not impossible, to automate pipelined design. In this paper, we target on multimedia streaming applications on heterogeneous multi-core...
In this paper, we describe challenges and solutions for programming multi-processor systems-on-a-chip, based on our experience in programming Platform2012, a large-scale multicore fabric under development by STMicroelectronics and CEA, using the MultiFlex multi-core programming environment.
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