Next Article in Journal
Next Article in Special Issue
Previous Article in Journal
Previous Article in Special Issue
Article Menu
Issue 7 (July) cover image

Export Article

Open AccessArticle
Sensors 2018, 18(7), 2256; https://doi.org/10.3390/s18072256

秒速赛车的漏洞是什么:A Novel Carrier Loop Algorithm Based on Maximum Likelihood Estimation (MLE) and Kalman Filter (KF) for Weak TC-OFDM Signals

School of Electronic Engineering, Beijing University of Posts & Telecommunications, No. 10 Xitucheng Road, Haidian District, Beijing 100876, China
*
Author to whom correspondence should be addressed.
Received: 16 May 2018 / Revised: 25 June 2018 / Accepted: 9 July 2018 / Published: 13 July 2018
(This article belongs to the Special Issue Selected Papers from UPINLBS 2018)

Abstract

Digital broadcasting signals represent a promising positioning signal for indoors applications. A novel positioning technology named Time & Code Division-Orthogonal Frequency Division Multiplexing (TC-OFDM) is mainly discussed in this paper, which is based on China mobile multimedia broadcasting (CMMB). Signal strength is an important factor that affects the carrier loop performance of the TC-OFDM receiver. In the case of weak TC-OFDM signals, the current carrier loop algorithm has large residual carrier errors, which limit the tracking sensitivity of the existing carrier loop in complex indoor environments. This paper proposes a novel carrier loop algorithm based on Maximum Likelihood Estimation (MLE) and Kalman Filter (KF) to solve the above problem. The discriminator of the current carrier loop is replaced by the MLE discriminator function in the proposed algorithm. The Levenberg-Marquardt (LM) algorithm is utilized to obtain the MLE cost function consisting of signal amplitude, residual carrier frequency and carrier phase, and the MLE discriminator function is derived from the corresponding MLE cost function. The KF is used to smooth the MLE discriminator function results, which takes the carrier phase estimation, the angular frequency estimation and the angular frequency rate as the state vector. Theoretical analysis and simulation results show that the proposed algorithm can improve the tracking sensitivity of the TC-OFDM receiver by taking full advantage of the characteristics of the carrier loop parameters. Compared with the current carrier loop algorithms, the tracking sensitivity is effectively improved by 2–4 dB, and the better performance of the proposed algorithm is verified in the real environment. View Full-Text
Keywords: carrier loop; MLE; LM; KF; TC-OFDM carrier loop; MLE; LM; KF; TC-OFDM
Figures

秒速赛车是哪里的开奖 www.0dv0k.cn Figure 1

Figure 1
<p>TC-OFDM signal Frame Structure.</p> ">
Figure 2
<p>Conventional carrier loop structure.</p> ">
Figure 3
<p>The principle of MLE.</p> ">
Figure 4
<p>LM algorithm flow chart.</p> ">
Figure 5
<p>The proposed carrier loop structure based on MLE and KF.</p> ">
Figure 6
<p>The Relationship between Loss of Lock Probability and SNR.</p> ">
Figure 7
<p>The RMS Frequency Tracking Error with SNR under different sample observations.</p> ">
Figure 8
<p>The residual carrier and phase convergence curve estimated by LM algorithm.</p> ">
Figure 9
<p>Frequency error comparison results by MLE and MLE&amp;KF.</p> ">
Figure 10
<p>Comparison results of frequency estimation errors by three algorithms under different SNR.</p> ">
Figure 11
<p>Comparison of the tracking probabilities between the three algorithms.</p> ">
Figure 12
<p>Each component of the modified base stations.</p> ">
Figure 13
<p>The TC-OFDM receiver. (<bold>a</bold>) is the internal and external structure of the TC-OFDM receiver; and (<bold>b</bold>) is the communication between the positioning receiver and the mobile phone.</p> ">
Figure 14
<p>Actual test diagram of the tracking sensitivity between the three algorithms.</p> ">
Figure 15
<p>The base station distribution of the test environment on the campus.</p> ">
Figure 16
<p>The RMSE positioning accuracy error in horizontal direction.</p> ">
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Liu, W.; Bian, X.; Deng, Z.; Mo, J.; Jia, B. A Novel Carrier Loop Algorithm Based on Maximum Likelihood Estimation (MLE) and Kalman Filter (KF) for Weak TC-OFDM Signals. Sensors 2018, 18, 2256.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
秒速赛车是哪里的开奖
Back to Top
  • 天生三条腿 半岁牛犊活成“牛坚强” 2019-02-20
  • 晋中市直机关将开展纪念建党97周年“红色+”系列活动 2019-02-20
  • 吴燕生任中国航天科技集团有限公司董事长 2019-02-20
  • 美国一大学将接受中国高考成绩 美媒:中国学子多了一条路 2019-02-19
  • 台媒曝吴建豪离婚 百亿身家娇妻收两封离婚协议书 2019-02-19
  • 娄勤俭确保江苏"四好农村路"建设走在全国前列 2019-02-18
  • 传媒每周热闻第360期:全国党报网站总编辑贺新春 央视春晚主持阵容曝光 2019-02-18
  • 13少年被逼参与盗窃遭烟头烫伤 21天撬130辆车 2019-02-18
  • 反思“天价账单”要看共性问题 2019-02-18
  • 西部网(陕西新闻网)www.cnwest.com 2019-02-17
  • 权健边路尖刀加盟初期曾被质疑 如今获球迷点赞 2019-02-17
  • 脱下警服当支书 老高回村以后(新时代·面孔) 2019-02-17
  • 党员干部注意了!这些事情不能做 2019-02-16
  • 甘肃裕河:“美猴王”下山 2019-02-16
  • China Fokus Richtungsweisende Zwei Tagungen stellen Weichen für neue ra“ 2019-02-15
  • 429| 562| 78| 173| 72| 213| 835| 53| 412| 298|