Predistortion in GSM has been introduced to deal with saturation in amplification at Base Transceiver Stations (BTS). This paper will focus on the elements and architectures in signal predistortion for one carrier and multicarrier modulations. The GCMAC neural network has been introduced as predistorter to provide the design with adaptive, digital and practical features. Some results are includ...

This paper presents a baseband predistorter to be used in OFDM systems operating with a nonlinear high power amplifier (HPA). Key features of the predistorter reside in the use of the HPA inverse structure as nonlinear distortion compensator. The performance of the compensated system is analyzed by simulations in an AWGN environment. The receiver also needs furthermore an equalizer in order to ...

Gain based predistorter (PD) is a highly effective and simple digital baseband predistorter which compensates for the nonlinear distortion of PAs. Lookup table (LUT) is the core of the gain based PD. This paper presents a discrete Newton’s method based adaptive technique to modify LUT. We simplify and convert the hardship of adaptive updating LUT to the roots finding problem for a system of two...

High-symbol-rate coherentoptical transceivers suffer more from the critical responses of transceiver components at high frequency, especially when applying a higher order modulation format. We recently proposed neural network (NN)-based digital pre-distortion (DPD) technique trained to mitigate response 128 GBaud optical coherent transmission system. In this paper, we further detail work and as...

In this paper, the data predistorter with memory used to minimize total power consumption due to amplifier nonlinearity in single power mode quadrature amplitude modulation(QAM) systems is investigated. The design of the data predistorter (DP) with memory is independent of the operating optimality criterion but depends upon the operating point of amplifier nonlinearity. The more useful choice o...

Objectives. To compare the efficacy of three placement techniques in marginal sealing of Class V composite restorations extending onto the root. Materials and Methods. Class V cavities were prepared on buccal surfaces of 30 extracted human molars, with gingival margins 1.5 mm on the root. Prepared teeth were randomly assigned into 3 groups of 10 each and restored with Single Bond/Filtek Supreme...

Abstract In a digital predistortion (DPD) system, accurate loop delay estimation is one of the prerequisites for precise calculation DPD coefficient. Multiplications plural numbers are needed in most conventional algorithms. Based on Euclidean (ELDE) method, this paper proposes simplified (SELDE) method that can avoid operation multiplication numbers. The ELDE and SELDE implemented actual under...

Modern modulation methods as used in 3rd generation mobile communications (UMTS) generate strongly fluctuating transmission signal envelopes with high peak-to-average power ratios. These properties result in significant distortion due to the nonlinear behavior of the radio-frequency power amplifier (RF PA). We propose different nonlinear model structures for such amplifiers, based on memory pol...