multiple access methods in satellite communication

... orthogonality among training sequences and introduce multiple access interference (MAI) To reduce the effect of the MAI, the authors find the CAZAC sequence that maximizes the signal-to-interference ratio ... Division Multiple Access With Polarization and Lin Jin discusses a potential multiple access and modulation scheme based on polarized states of electromagnetic (EM) waves for Line-of-Sight (LOS) communications ... Special Issue contains 21 selected articles, covering a significant number of hot topics in Multiple Access Communications such as new cooperative MAC protocols; spectrum sharing, and channel assignment

Ngày tải lên: 21/06/2014, 17:20

... orthogonal access fading channels in wireless sensor networks— optimal and suboptimal estimatorsmultiple-Xin Wang∗1 and Chenyang Yang1 1 School of Electronics and Information Engineering, Beihang ... results in [19], indicatethat the separate source-channel coding scheme is optimal in fading channels with orthogonal multiple-accessprotocols, which outperforms AF transmission, a simple joint source-channel ... the sensors can transmit training symbols to facilitatechannel estimation The training symbols can be incorporated into the message function c(x) Then, theMLE with training symbols available is

Ngày tải lên: 20/06/2014, 04:20

... supervised learning methods can infer models of pitch combinationsseen in the training stage, but they are currently constrained to monotimbralsounds with almost constant spectral profiles [4] In music, ... processing stages, shown in Figure 1, are described below 2.1 Preprocessing The analysis is performed in the frequency domain, computing the magnitudespectrogram using a 93 ms Hanning windowed ... frame Therefore, vertical lines inthe plot usually indicate errors in assigning harmonic components 3.2 Pitch tracking A basic pitch tracking method is introduced in order to favor smooth transitions

Ngày tải lên: 21/06/2014, 17:20

... CwA in inclusive classes in preschools Currently, there is no research result published in Vietnam comprehensively focusing on developing communication skills for CwA in inclusive classes in preschool ... degree who are all learning in inclusive preschool classes - Investigation location: in Cau Giay, Dong Da, Ba Dinh districts in Hanoi * Investigation methods and tools Methods - Questionnaire: ... CwA to learn in inclusive classes CwA learning in inclusive classes have less atypical behaviors CwA learning in inclusive environment in which they are treated equally with no discrimination and

Ngày tải lên: 02/07/2014, 20:28

... used in a reference subchannel in a reference cell are distributed in different subchannels in the reuse cells The subcarriers used in a subchannel in a certain cell are unlikely to be repeated in ... MAPPING FROM SUBCARRIERSUSE OF OFDMA IN WIMAX AND LTE Subcarriers are the smallest granular units in the frequency domain, OFDM symbol duration is the smallest granular unit in the time domain in ... Orthogonal Frequency Division Multiple Access in WiMAX and LTE: A Comparison Group 4 – Trang 2 INTRODUCTION USE OF OFDMA IN WIMAX AND LTE  NETWORK ENTRY STEPS IN WIMAX AND LTE  PERFORMANCE

Ngày tải lên: 24/07/2015, 22:26

... cập nhật các thông tin này sử dụng các bản tin tin cậy được định nghĩa theo tiêu chuẩn Dựa trên điều này, trạm gốc sẽ chọn 2 bin trong một trong số các băng và phân bố những bin như vậy cho 3 ký ... kề nhau được sắp xếp trong một nhóm, được gọi là các bin, như trong hình 5 Mỗi bin có 8 sóng mang dữ liệu và một sóng điều khiển, và 4 bin liền kề thì được nhóm vào một band Người dùng gửi dữ ... fading lựa chọn, [4] Ngoài ra, tần số đa dạng và kênh thông tin phản hồi có thể được sử dụng hiệu quả để cải thiện sức mạnh và thông lượng [4] Do đó, (OFDM) được ưu tiên trong hệ thống thông tin

Ngày tải lên: 24/07/2015, 22:27

... Interference Suppression in OFDMA Uplink 9 1.4 Outline 12 Chapter 2 Inter-Carrier Interference in OFDMA System Uplink 13 2.1 Frequency Asynchronism and ICI in OFDMA Uplink 13 2.2 A Review ... signal-to-noise power ratio MAI multiple access interference TDMA time division multiple access MF matched filtering WiMAX worldwide interoperability microwave access Trang 10Summary In current broadband ... Division Multiple Access (FDMA), becomes a paramount candidate to support multiple access in future broadband wireless systems due to its advantages over existing multi-access techniques In uplink

Ngày tải lên: 14/09/2015, 14:03

... communication High speed multiple access communication over short ranges faces the challenge of multipath fading in indoor wireless channels Instead of increasing the transmit power, increasing ... deliver in a channel with many impairments These impairments include thermal noise, fading and shadowing, multiple access interference and interference from external sources Calculating the Trang ... multipaths is much less, and in indoor channels it Trang 29can be used as the preliminary step in developing the analysis towards fading channels 3.2 Multiple access interference model The impulse

Ngày tải lên: 05/10/2015, 22:04

... relative humidity In the first half of winter, the relative humidity is quite low in the Northeast and North Delta It increases during the remaining winter period due to heavy, drizzly rains and then ... data interpolation Some research indicates that Kriging-based interpolation methods have higher accuracy and lower bias than other geo-statistical methods [18,19] These methods are a linear combination ... other methods [5,6] Some work conducting research Kriging interpolation in their country-level data were reported [7-9] A total of 922 meteorological stations in the U.S were interpolated using

Ngày tải lên: 12/12/2017, 14:44

... apply the knowledge in actual communication For this, we need to have innovative teaching methods so that each class students are more interested in active learning and memory training class at all ... following reasons: The international phonetic alphabet is used in learning a new language for pronunciation and hearing ability It is also used in voice training for students to have an inspiring ... their knowledge In the process of teaching, revision lessons as well as tutoring weak students or fostering good students, we must integrate the following contents: In addition to teaching the English

Ngày tải lên: 21/10/2019, 10:59

... apply the knowledge in actual communication For this, we need to have innovative teaching methods so that each class students are more interested in active learning and memory training class at all ... following reasons: The international phonetic alphabet is used in learning a new language for pronunciation and hearing ability It is also used in voice training for students to have an inspiring ... their knowledge In the process of teaching, revision lessons as well as tutoring weak students or fostering good students, we must integrate the following contents: In addition to teaching the English

Ngày tải lên: 31/10/2019, 09:49

... constraint The findings of the study are in line with that of Baig et al., (1995) and Omar et al., (2012) Individual constraints Data in Table 2 and Figure 2(c) under individual constraints ... For farmers, the constraints were studied at field level, institutional level and individual constraints The constraints are discussed in the following subheads Constraints in adoption of scientific ... husbandry departments in executing extension works’ as important constraint The study is in agreement with the findings of APO (2006) which states that the availability of insufficient finances and at

Ngày tải lên: 29/05/2020, 17:58

... apply the knowledge in actual communication For this, we need to have innovative teaching methods so that each class students are more interested in active learning and memory training class at all ... following reasons: The international phonetic alphabet is used in learning a new language for pronunciation and hearing ability It is also used in voice training for students to have an inspiring ... their knowledge In the process of teaching, revision lessons as well as tutoring weak students or fostering good students, we must integrate the following contents: In addition to teaching the English

Ngày tải lên: 18/07/2020, 07:18

... other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. Trademark ... without intent to infringe. First published 2010 by Pearson Education Inc. Library of Congress Cataloging in Publication Data Names: Leslie, Larry Z author. Title: Communication research methods in ... attendance is declining, families are increasingly fragmented, and schools seem to spend as much time coping with violence and administering tests as teaching Our culture is bombarded with information

Ngày tải lên: 28/07/2020, 00:15

... extremely large in the case of unconstrained channel access, resulting in a low inherent statistical multiplexing gain. By combining CDMA with PRMA, it is possible to control the access of users ... 46 2.6 Summary 48 3 Multiple Access in Cellular Communication Systems 49 3.1 Multiple Access and the OSI Layers 49 3.2 Basic Multiple Access Schemes 53 3.3 Medium Access Control in 2G Cellular Systems ... (P loss ) max in multiples of σ K d Hamming distance d il Interleaving depth d min Minimum Hamming distance e Error correcting capability of an (L, B, e) block code; also 2.718 282 f CAF Channel access...

Ngày tải lên: 02/03/2013, 16:59

... Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechweb.org Advances in Satellite Communications, ... capabilities. In addition, a satellite link engineer has to consider the constrains of the communication channel; so many radio frequency calculations are needed, these include link budget analysis, ... 1 Antennas in Satellite Communications Advances in Satellite Communications Edited by Masoumeh Karimi and Yuri Labrador Published by InTech Janeza Trdine 9, 51000...

Ngày tải lên: 19/06/2014, 19:20

... & King, 1979). As the wave velocities in a finite helix are hard to calculate, those calculated for the infinite Advances in Satellite Communications 10 The existence of multiple ... et al., 2006). In this chapter, we introduce a design of the helical antenna obtained by combining two methods to improve the radiation properties of this antenna; one is changing the pitch angle, ... lengths were varied in order to obtain a wider bandwidth with higher antenna gain. In (Skiljo et al., 2010) the axial mode bandwidth was examined by means of parameters defining the limits of...

Ngày tải lên: 19/06/2014, 19:20

... z    M μν (z) M μν (0)=M in μν (0), (9) Fig. 3. Model of wave propagation in an inhomogeneous random medium. 32 Advances in Satellite Communications 2 Will-be-set-by -IN- TECH Fig. 1. Spot dancing and wave ... However, because a carrier frequency becomes higher according to the increase in the required channel capacity of satellite communication links in the next generation, the analysis of the effects of ... shorter in order to achieve a phase lag of 45°. Instead of infinite balun, we proposed a stripline structure for impedance matching and the support for helical wire. Fig. 15 c) shows that matching...

Ngày tải lên: 19/06/2014, 19:20

... process of representing information in a more compact form by eliminating redundancies in the original data representation (Pu, 2006). Due to the presence of redundancies in the original representation, ... antenna in order to satisfy the required EIRP from the point of view of the decrease in an in uence of atmospheric turbulence on BER in the uplink. 3.3.2 Downlink For the downlink, we can obtain BER ... flow information before undergoing compression in order to increase compression ratio. Unfortunately, IPzip may not suit for real-time processing as it needs to carry out offline training to...

Ngày tải lên: 19/06/2014, 19:20

... original form. The original block of packets will be divided into individual packets according to the original size of each combined packet. After that, these individual packets are stored in ... Advances in Satellite Communications 76 Fig. 17. The packet drop rate distribution in Scenario 2. The proposed scheme succeeds in reducing the packet drop rate by 1 – 90 percent in Scenario ... scheme in satellite network topology is shown in Figure 10 below. As stated earlier, the main objective of this research study is to overcome the limitation and constraints of satellite communication...

Ngày tải lên: 19/06/2014, 19:20