Sweety Badhwar et al. Int. Journal of Engineering Research and Applications www.ijera.com ISSN : 2248-9622, Vol. 4, Issue 9( Version 3), September 2014, pp.01-03 www.ijera.com 1 | Page Design of Digital Predistortion Technique for RF Power Amplifier using Memory Polynomial Er. Sweety Badhwar *, Er. Bimaljeet Kaur **, Er. Gaurav Badhwar***, Dr. Amandeep Singh Sappal**** *,**,***,**** (Department of Electronics and Communication, Punjabi University, Patiala, Punjab, India) ABSTRACT Linearization of power amplifier has been an area of intense research from the last many years. The various types of linearization techniques are available for linearising PA but Digital Predistortion technique has been observed as one of the most common and effective method. But due to the issues like memory effects and exact characterization of non-linear behaviour of power amplifier, the implementation of existing predistortion technique suffers. So in this paper, a digital predistorter based on memory polynomial has been proposed that takes care of above mentioned issues. The presented technique is easy to implement and simple. Keywords - AM/AM characteristics, Digital Predistortion (DPD), Memory polynomial, Power Amplifier (PA), Power Spectral Density (PSD). I. Introduction Now a days, wireless communication standards has focused on an intensive use of employing modulation schemes which require both high linearity and high efficiency power amplifiers to enhance spectrum efficiency and also to satisfy the increasing demand in transmission data rates. It is usually desirable to operate the PA near its saturation region in order to obtain high power efficiency; however, this means that nonlinear distortions are introduced at the output of the PA, which are undesirable specially when the input signal has a varying amplitude. Therefore a trade-off between the efficiency and linearity is always there. Non- linearity not only causes distortion but also degrades the bit error rate (BER) performance of power amplifier. To achieve both the high efficiency and the high linearity simultaneously in power amplifier design, is the most challenging task. Therefore, linearization of nonlinear power amplifiers has gained significant interest. Many techniques are available to compensate the nonlinearities of PA but among these DPD method is of more concern as it provides high efficiency and good linearity. Different types of predistortion techniques have been proposed earlier, but they are complex to implement. So in this paper a digital predistorter using a memory polynomial has been proposed, which is simple and easy to implement. The organization of the paper is as follows: Section 1 is Introduction, Section 2 presents proposed digital predistortion technique and Section 3 presents simulation results. Finally, a conclusion is drawn in Section 4. II. Proposed Digital Predistorter Pre-distortion technique is one of the most efficient linearization techniques. Fig. 1 Predistortion Technique It consists of a pre-distorter which proceeds the nonlinear power amplifier and has inverse transfer characteristics of that of the power amplifier. Thus makes the overall amplification of system nearly linear. Fig. 2 Basic Steps of Pre-Distortion Technique RESEARCH ARTICLE OPEN ACCESS