Download or read book Co channel Interference Cancellation for OFDM Systems Using the Expectation Maximization Algorithm written by Vikrant Venkateshwar Gunna Srinivasan and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study on Co channel Interference Cancellation Algorithms for OFDM Based Mobile Communication Systems written by Zhenyu Zhou and published by . This book was released on 2011 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Channel Estimation Algorithms for OFDM in Interference Scenarios written by Farah Zaarour and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The scarcity of the radio spectrum and the increasing demand on bandwidth makes it vital to optimize the spectrum use. While a maximum efficiency should be attained, a minimal interference level should be maintained. OFDM has been selected as the modulation scheme in several wireless standards. Channel estimation is a fundamental task in OFDM and it becomes even more challenging in the presence of interference. In this thesis, our aim is to propose channel estimation algorithms for OFDM systems in the presence of interference, where conventional channel estimators designed for OFDM fail. First, we consider the cognitive radio environment and propose a novel channel estimation framework for fast time-varying channels in OFDM with NBI. This is accomplished through an expectation maximization (EM) based algorithm. This formulation allows us to obtain a closed-form expression for the estimation of the noise power. In this thesis, we are particularly interested in a very recent scheme of superimposed pilots for OFDM (DNSP). DNSP assures interference-free pilots at the expense of data interference. Seen the modernity of DNSP, a suitable receiver has to be designed to cope with its design. We first propose a low-complexity interference canceler (IC) for slow time-varying channels with DNSP. The performance of the proposed IC is guaranteed when the channel estimation error is small. As another contribution, we extend the design of the approximated IC for DNSP so as to take the channel estimation errors into account. Finally, we consider robust channel estimation which can be viewed as one of the perspectives of this thesis.

Download or read book Avoiding Effects of OFDM Adjacent Channel Interference by Using Combinations of Modulation Schemes written by Le Tien Anh and published by GRIN Verlag. This book was released on 2009-05 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master's Thesis from the year 2008 in the subject Engineering - Communication Technology, grade: erfolgreich bestanden, Keio University (Graduate school of Science and Technology - School of Science for Open and Environmental Systems), language: English, abstract: Non-orthogonality among adjacent OFDM channels creates OFDM adjacent channel interference and it heavily affects the entire system's performance. Conventional methods to avoid OFDM adjacent channel interference are not only insufficient but also are wasting a lot of frequency resources. In this research, a method using combinations of modulation schemes is proposed to avoid effects of OFDM adjacent channel interference. It can be obtained by modulating the sub-carriers at the outer sides of an OFDM channel with lower order modulation schemes (such as BPSK or QPSK), while modulating the sub-carriers at the inner side of the OFDM channel with higher order modulation schemes (such as 16QAM or 64QAM). Intensive simulations have been carried out to evaluate the performance of the proposed method. The simulation results have shown an increase in the OFDM system's resistance against adjacent channel interference while still maintain the bandwidth efficiency.

Download or read book Co channel Interference Suppression for Ofdm Systems written by Jonghyun Won and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: We propose new methods for co-channel interference suppression in orthogonal frequency division multiplexing (OFDM) systems with multiple receive antennas. Our methods use a low-order time-domain model to parameterize the matrix-valued spectral density of the noise and interference. A penalized maximum likelihood-function approach is used to choose the proper model order automatically in each received data frame. We show that these methods significantly improve the symbol-error-rate when interference exists in the received data. Numerical examples are provided to illustrate the performance of our new methods and compare with conventional methods. We also discuss the diplus or minusculties associated with the application of our method to space-time OFDM (ST-OFDM).

Download or read book Upplysningar om den elektriska belysningen och dennas nuvarande st ndpunkt written by and published by . This book was released on 1888 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interference Cancellation Using Space Time Processing and Precoding Design written by Feng Li and published by Springer Science & Business Media. This book was released on 2012-07-11 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interference Cancellation Using Space-Time Processing and Precoding Design introduces original design methods to achieve interference cancellation, low-complexity decoding and full diversity for a series of multi-user systems. In multi-user environments, co-channel interference will diminish the performance of wireless communications systems. In this book, we investigate how to design robust space-time codes and pre-coders to suppress the co-channel interference when multiple antennas are available. This book offers a valuable reference work for graduate students, academic researchers and engineers who are interested in interference cancellation in wireless communications. Rigorous performance analysis and various simulation illustrations are included for each design method. Dr. Feng Li is a scientific researcher at Cornell University.

Download or read book Channel Impulse Response Length Estimation and Interference Cancellation for OFDM Systems written by Vǎn-Đúc Nguyên and published by . This book was released on 2004 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Interference Cancellation Methods in MIMO OFDM Systems written by Sreekanth Neriyanuru and published by LAP Lambert Academic Publishing. This book was released on 2015-01-19 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, Survey and investigation on inter symbol interference (ISI) and inter carrier interference (ICI) due to either carrier frequency offset or timing offset issues and interference mitigation schemes available, compare and analyze their bit error rate performance to various schemes for OFDM and MIMO-OFDM systems. Efforts have been made to develop an efficient interference cancelling receiver for ISI and ICI, algorithms to be implemented on MATLAB environment for OFDM and MIMO-OFDM which are not available in literature.

Download or read book Advanced Interference Suppression Schemes for OFDM Systems written by K.M. Zahidul Islam and published by . This book was released on 2011 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: We also investigate computationally efficient reliable OFDM downlink signal detection algorithm in presence of relatively strong co-channel interference (CCI) from adjacent interfering base transceiver station (BTS). We propose and compare the performance of several per-subcarrier based CCI cancellation algorithms considering 1 and 2 receive antennas at the user terminal.

Download or read book Co channel Interference Cancellation for TDMA Cellular Systems written by Gordon L. Stüber and published by . This book was released on 1996 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improved Inter subchannel Interference Cancellation for OFDM Systems written by 高明駿 and published by . This book was released on 2008 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Co channel Interference Cancellation for DS SS CDMA Mobile Communication System written by Kamel Mostafa Shaheen and published by . This book was released on 1997 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Co channel Interference Mitigation in Reuse 1 Cellular OFDM Systems written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pilot Aided Cyclo stationary Detection and Active Interference Cancellation for OFDM Systems in the Presence of RF Impairments written by Arash Zahedi-Ghasabeh and published by . This book was released on 2011 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Low Complexity Co channel Interference Cancellation written by Thorben Detert and published by . This book was released on 2008 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Co channel Interference Cancellation in Mobile Cellular Communication Systems written by Reza Berangi and published by . This book was released on 1998 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt: