From the Publisher: 
This is undoubtedly the most accessible book on digital signal processing (DSP) available to the beginner. Using intuitive explanations and well-chosen examples, this book gives you the tools to develop a fundamental understanding of DSP theory. The author covers the essential mathematics by explaining the meaning and significance of the key DSP equations. Comprehensive in scope, and gentle in approach, the book will help you achieve a thorough grasp of the basics and move gradually to more sophisticated DSP concepts and applications.

数字信号处理 = Understanding digital signal processing

A single-mode Yb-doped fiber laser producing 2 W CW at 978 nm is demonstrated with a high slope efficiency of 72%. Thanks to its narrow bandwidth, lower than 0.02 nm, and its tunability of 6 nm, it has been efficiently frequency doubled in a periodically poled MgO:LiNbO3 waveguide, leading to a power of 83 mW at 489 nm and an internal conversion efficiency of 26 %.

Frequency doubling of an efficient continuous wave single-mode Yb-doped fiber laser at 978 nm in a periodically-poled MgO:LiNbO3 waveguide.

A continuous-wave (CW) master oscillator-power amplifier (MOPA) fiber source, tunable around 978 nm, was frequency-doubled to 488.7 nm. Both the laser and the amplifier were made with cladding-pumped jacketed air-clad Yb-doped fibers. The MOPA generated up to 2.7 W of power in an output beam with an M/sup 2/ value of 1.8. This was frequency-doubled in a periodically poled potassium titanyl phosphate crystal at room temperature, in a single-pass configuration. The generated blue light had a CW power of 18.1 mW, a nearly Gaussian spatial intensity profile, and an M/sup 2/ value of 1.7.

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A 980-nm Yb-doped fiber MOPA source and its frequency doubling

Design of hardware efficient FIR filter: A review of the state-of-the-art approaches

Digital signal processing (DSP) circuits are extremely important in computing and communications areas One application of DSP is a Finite impulse response (FIR) filter The principle objective of this exploration is to present a methodology for an upgraded framework of a FIR digital filter from software level to the hardware level It includes the selection of design method, structure and cost effective hardware utilization Theoretical and experimental results performed FIR band pass filter suggests that the window design method is relatively simple and easy to use because of the availability of well-defined equation Comparison presented that Kaiser window gives the minimum main-lobe width and a sharp cut-off which means this window has less transition width and the study showed that the Direct-Form structure approach is simpler and offers a better performance than other common filter structures It results in low cost, reduced area and more robust to withstand the quantization errors For effi

Design and implementation of an efficient FIR digital filter

A cladding-pumped ytterbium-doped jacketed air clad fiber laser operating at 977 nm generates a record-breaking 3.5 W of output power in a nearly diffraction-limited output beam, with a slope efficiency of 42% and a threshold of 410 mW with respect to launched power.

/pdf/a-3-5-w-977-nm-cladding-pumped-jacketed-air-clad-ytterbium-1zxb6sc81e.pdf

A 3.5 W 977 nm cladding-pumped jacketed air-clad ytterbium-doped fiber laser

In this paper, we propose higher point FFT (fast Fourier transform) algorithms for a single delay feedback pipelined FFT architecture considering the 4096-point FFT These algorithms are different from each other in terms of twiddle factor multiplication. Twiddle factor multiplication complexity comparison is presented when implemented on Field-Programmable Gate Arrays(FPGAs) for all proposed algorithms. We also discuss the design criteria of the twiddle factor multiplication. Finally it is shown that there is a trade-off between twiddle factor memory complexity and switching activity in the introduced algorithms.

/pdf/4k-point-fft-algorithms-based-on-optimized-twiddle-factor-24lp00sfb9.pdf

4k-point FFT algorithms based on optimized twiddle factor multiplication for FPGAs

Logarithmic number system (LNS) is an attractive alternative to realize finite-length impulse response filters because of multiplication in the linear domain being only addition in the logarithmic domain. In the literature, linear coefficients are directly replaced by the logarithmic equivalent. In this paper, an approach to directly optimize the finite word length coefficients in the LNS domain is proposed. This branch and bound algorithm is implemented based on LNS integers and several different branching strategies are proposed and evaluated. Optimal coefficients in the minimax sense are obtained and compared with the traditional finite word length representation in the linear domain as well as using rounding. Results show that the proposed method naturally provides smaller approximation error compared to rounding. Furthermore, they provide insights into finite word length properties of FIR filters coefficients in the LNS domain and show that LNS FIR filters typically provide a better approximation error compared to a standard FIR filter.

/pdf/design-of-finite-word-length-linear-phase-fir-filters-in-the-xv5wmliq3e.pdf

Design of finite word length linear-phase FIR filters in the logarithmic number system domain

Summary form only given. Here, we present a Q-switched 980 nm cladding-pumped YDFL with 1.2 /spl mu/J of energy and 60 W of peak power in pulses shorter than 20 ns at repetition rates of up to /spl sim/0.2 MHz and 250 mW of average output power for repetition rates between 0.2 and 0.65 MHz. A pulsed 980 nm source with high peak power and good beam quality is attractive for frequency conversion, e.g. frequency quadrupling to 245 nm.

Q-switched 980 nm Yb-doped fiber laser

FIR filters occupy a central place many signal processing applications which either alter the shape, frequency or the sampling frequency of the signal. FIR filters are used because of their stabili ...

/pdf/techniques-for-efficient-implementation-of-fir-and-particle-yo5ford5hb.pdf

Syed Asad Alam

Papers

A 3.5 W 977 nm cladding-pumped jacketed air-clad ytterbium-doped fiber laser

4k-point FFT algorithms based on optimized twiddle factor multiplication for FPGAs

Design of finite word length linear-phase FIR filters in the logarithmic number system domain

Q-switched 980 nm Yb-doped fiber laser

Techniques for Efficient Implementation of FIR and Particle Filtering