We present cycle-static dataflow (CSDF), which is a new model for the specification and implementation of digital signal processing algorithms. The CSDF paradigm an extension synchronous that still allows static scheduling and, thus, very efficient application. In comparison with dataflow, it more versatile because also supports algorithms cyclically changing, but predefined, behavior. Our examples show this capability results in higher degree parallelism hence, throughput, shorter delays,...

The average bit-error rate of transmit antenna selection combined with receive maximum-ratio combining is computed as a function the update when using binary phase-shift keying in flat Rayleigh fading channels. This scheme achieves an order diversity equal to product number and antennas. Therefore, it can gain significant benefits over traditional schemes by distributing antennas side.

Nowadays, a lot of effort is spent on developing inexpensive orthogonal frequency-division multiplexing (OFDM) receivers. Especially, zero intermediate frequency (zero-IF) receivers are very appealing, because they avoid costly IF filters. However, zero-IF front-ends also introduce significant additional front-end distortion, such as IQ imbalance. Moreover, does not solve the phase noise problem. Unfortunately, OFDM sensitive to receiver nonidealities imbalance and noise. Therefore, we...

Orthogonal frequency-division multiplexing (OFDM), with the help of a cyclic prefix, enables low complexity frequency domain equalization, but suffers from high crest factor. Single carrier prefix (SC-CP) has same advantage similar performance, lower factor and enhanced robustness to phase noise. The is overhead, so we put more information in it by implementing this as training sequence (TS). This new aided equalized single (TASC) scheme offers us additional known symbols better...

Two major technical challenges in the design of future broadband wireless networks are impairments propagation channel and need for spectral efficiency. To mitigate impairments, orthogonal frequency division multiplexing (OFDM) can be used, which transforms a frequency-selective set frequency-flat channels. On other hand, to achieve higher efficiency, space multiple access (SDMA) reuses bandwidth by signals based on their spatial signature. In this paper, we present combined OFDM/SDMA...

The high sample-rates involved in many DSP-applications, require the use of static schedulers wherever possible. construction schedules however is classically limited to applications that fit synchronous data flow model. In this paper we present cyclo-static as a model describe with cyclically changing behaviour. We give both necessary and sufficient condition for existence schedule graph show how such can be constructed. example video encoder used illustrate importance real-life DSP-systems.

We propose a rapid-prototyping setup to minimize development cost and structured-prototyping methodology reduce programming effort. The general-purpose hardware consists of commercial DSP processors, bond-out versions core field-programmable gate arrays (FPGAs) linked form powerful, heterogeneous multiprocessor, such as the Paradigm RP developed within Retides (Real-Time Emulation System) Esprit project. Our Graphical Rapid Prototyping Environment (Grape-II) automates prototyping for these...

Orthogonal frequency-division multiplexing with cyclic prefix enables low-cost frequency-domain mitigation of multipath distortion. However, to determine the equalizer coefficients, knowledge channel frequency response is required. While a straightforward approach measure known pilot symbol sequence, existing literature reports significant performance gain when exploiting correlation properties channel. Expressing this by finite delay spread, we build deterministic model parametrized impulse...

Substrate coupling in mixed-signal IC's can cause important performance degradation of the analog circuits. Accurate simulation is therefore needed to investigate generation, propagation, and impact substrate noise. Recent studies were limited time-domain behavior generated noise injection from a single source. This paper focuses on generation by digital circuits spectral content this To simulate SPICE model for heavily doped epi-type substrates has been used. The accuracy verified with...

Zero-IF receivers are gaining interest because they enable low-cost WLAN OFDM terminals. However, zero-IF introduce IQ imbalance which may have a huge impact on performance. Rather than increasing component cost to decrease the imbalance, an alternative is tolerate and compensate it digitally. Current solutions converge too slowly for bursty communication. Moreover, tremendous of frequency offset estimation/compensation problem not considered. We analyze joint IQ-CFO propose low-cost, highly...

Today a lot of attention is spent on developing inexpensive OFDM receivers. Especially, zero-IF receivers are very appealing, because they avoid costly IF filters. However, this implies IQ demodulation at RF, which therefore cannot be done digitally and thus introduces mismatch. Unfortunately, sensitive to receiver imbalance. Therefore, we developed new compensation scheme combat the imbalance baseband. In paper, describe algorithm represent performance results. Our eliminates almost...

A C++ based programming environment for the design of complex high speed ASICs is presented. The a 75 Kgate DECT transceiv er used as driv example. Compact descriptions, combined with efficient sim ulationand syn thesis strategies are essen tial such system. It sho wn how approach outperforms traditional HDL-based methods.

Turbo codes are the most recent breakthrough in coding theory. However, decoder's implementation cost limits their incorporation commercial systems. Although decoding algorithm is highly data dominated, no true memory optimization study has been performed yet. We have extensively and systematically investigated different optimizations for maximum a posteriori (MAP) class of algorithms. It turns out that it not possible to present one decoder structure as being optimal. In fact, there several...

We propose a new stochastic model for the time-variance of channels fixed wireless communications. In classical Jakes' Doppler spectrum, receiver (or transmitter) is assumed to move at certain speed. However, in communication systems, both transmitter and are stationary time-variations actually due moving scatterers. A novel this sort time-varying introduced specifically indoor environments, which can be employed more accurately simulate performance

The use of computer-aided software engineering (CASE) tools for stream-oriented real-time digital signal processing (DSP) applications is discussed. These are characterized by a continuous stream data samples or blocks arriving at the facility time instances completely determined outside world. An overview existing development DSP given. CASE tool GRAPE (graphical programming environment), which allows easy programming, compiling, debugging and evaluating high-frequency systems, presented....

The implementation of embedded networked appliances requires a mix processor cores and HW accelerators on single chip. When designing such complex heterogeneous SoCs, the / SW partitioning decision needs to be made prior refining system description. With OCAPI-xl, we developed methodology in which can anywhere design flow, even just doing code-generation for both SW. This is possible thanks refinable, implementable, architecture independent OCAPI-xl model was used develop stand alone,...

Substrate noise caused by large digital circuits will degrade the performance of analog located on same substrate. To simulate this degradation, total amount generated substrate must be known. Simulating is however not feasible with existing circuit simulators and detailed models due to long simulation times high memory requirements. We have developed a methodology generation at higher level. Not only does take coupling from switching gates into account, but also power supply included. This...

Future high-performance wireless communication applications such as local area networks (WLANs) around 5 GHz require low-power and highly integrated transceiver solutions. The integration of the RF front end especially poses a great challenge in these applications, traditional front-end implementations large number external passive components. In this paper, we present single-package complete transceivers based on thin-film multichip module (MCM) technology with passives. MCM substrate is...

New OFDM-based WLAN standards target wireless communications in the 5 GHz band for consumer multimedia applications. Given high data rates with required low bit error rates, and given nature of OFDM signal, a conservative analysis front-end requirements lead to severe, over dimensioned specifications. Such design would never meet this market, by necessity low-cost low-power. To extract more optimal specifications, we assess BER performance complete WLAN-OFDM link. As result, first show that...

The combination of space-time block coding (STBC) and direct-sequence code-division multiple access (DS-CDMA) has the potential to increase performance users in a cellular network. However, if not carefully designed, resulting transmission scheme suffers from increased multiuser interference (MUI), which dramatically deteriorates performance. To tackle this MUI problem downlink, we combine two specific DS-CDMA STBC techniques, namely single-carrier (SCBT) time-reversal STBC. allows for...

This paper addresses the problem of minimizing memory size and accesses in multiresolution texture coding architectures for discrete cosine transform (DCT) wavelet-based schemes used, example, virtual-world walk-throughs or facial animation scenes an MPEG-4 system. The cost is important since accesses, bandwidth limitations, general correct handling data flows have become true critical issues designing high-speed low-power video-processing efficiently using multimedia processors. For...