A CDMA system wideband feedforward linearizer design based on an analytical model

2003-01-01
Coskun, AH
Demir, Şimşek
Feedforward systems are complicated due to the presence of two nonlinear amplifiers and the requirement of amplitude, delay and phase match in two different loops. Analytical tools that characterize this complexity help the designer a lot in rapid and accurate initial optimizations, particularly for wideband applications. In this work we present a wideband feedforward linearizer design for CDMA applications, based on an analytical model and speed and accuracy aspects of the results are compared with RF simulations performed by real power amplifiers and components.
IEEE Radio and Wireless Conference (RAWCON 2003)

Suggestions

Application of an analytical model to an actual CDMA system feedforward linearizer
Coskun, A. Hakan; Demir, Şimşek (2003-01-01)
Analysis and design of feedforward systems are complicated due to the presence of two nonlinear amplifiers and the requirement of amplitude, delay, and phase match in two different loops. For this reason, analytical tools are hard to develop but are required for initial designs and understanding of the system performance. Relation of the actual systems and the models based on certain assumptions is necessary. In this work we extend the previously developed analytical model and present the verifications with...
A novel two-step pseudo-response based adaptive harmonic balance method for dynamic analysis of nonlinear structures
Sert, Onur; Ciğeroğlu, Ender (Elsevier BV, 2019-09-01)
Harmonic balance method (HBM) is one of the most popular and powerful methods, which is used to obtain response of nonlinear vibratory systems in frequency domain. The main idea of the method is to express the response of the system in Fourier series and converting the nonlinear differential equations of motion into a set of nonlinear algebraic equations. System response can be obtained by solving this nonlinear equation set in terms of the unknown Fourier coefficients. The accuracy of the solution is great...
A Method For Fine Resolution Frequency Estimation From Three DFT Samples
Candan, Çağatay (2011-06-01)
The parameter estimation of a complex exponential waveform observed under white noise is typically tackled in two stages. In the first stage, a coarse frequency estimate is found by the application of an N-point DFT to the input of length N. In the second stage, a fine search around the peak determined in the first stage is conducted. The method proposed in this paper presents a simpler alternative. The method suggests a nonlinear relation involving three DFT samples already calculated in the first stage to...
A High performance automatic mode-matched MEMS gyroscope
Sönmezoğlu, Soner; Demir, Şimşek; Department of Electrical and Electronics Engineering (2012)
This thesis, for the first time in the literature, presents an automatic mode-matching system that uses the phase relationships between the residual quadrature and drive signals in a gyroscope to achieve and maintain the frequency matching condition, and also the system allows controlling the system bandwidth by adjusting the closed loop parameters of the sense mode controller, independently from the mechanical sensor bandwidth. There are two mode-matching methods, using the proposed mode-matching system, p...
A Low-Complexity Graph-Based LMMSE Receiver for MIMO ISI Channels With M-QAM Modulation
Sen, Pinar; Yılmaz, Ali Özgür (2017-02-01)
In this paper, we propose a low complexity graph-based linear minimum mean-square-error (LMMSE) equalizer in order to remove inter-symbol and inter-stream interference in a multiple input multiple output (MIMO) communication. The proposed state space representation inflicted on the graph provides linearly increasing computational complexity with block length. In addition, owing to the Gaussian assumption used in the presented cycle-free factor graph, the complexity of the suggested equalizer structure is no...
Citation Formats
A. Coskun and Ş. Demir, “A CDMA system wideband feedforward linearizer design based on an analytical model,” presented at the IEEE Radio and Wireless Conference (RAWCON 2003), Massachusetts, Amerika Birleşik Devletleri, 2003, Accessed: 00, 2022. [Online]. Available: https://hdl.handle.net/11511/95435.