Research on Uplink Channel Estimation Method in TD-LTE System

2011 ◽  
Vol 135-136 ◽  
pp. 847-851
Author(s):  
Cui Zhen Sun ◽  
Zhao Hua Zeng

LTE is a long term evolution scheme of 3GPP, as a using extensively communication standards, it has higher data rate and higher quality. Channel estimation plays a quite important role in the LTE system which requires the high data rate and quality. In the article, based on the analysis of the LS and MMSE algorithms of the LTE system, a advised algorithm is adopted. The pilot signal is processed before the channel estimation by reducing noise in time domain. The simulation results demonstrate that the advised algorithm is a preferable choice in estimation performance, simultaneously; the advised has obviously reduced the algorithm complexity.

2012 ◽  
Vol 433-440 ◽  
pp. 3847-3851
Author(s):  
Zhao Hua Zeng ◽  
Li Jun Xue ◽  
Qian Zhao

As users of the increasing demand for multimedia services, 3GPP long term evolution system proposed the Long Term Evolution, LTE. LTE is the most important improvements with a new air interface technology to provide users with higher peak rates. Accurate channel estimation is to ensure the transmission quality of LTE system and the key to its advantages. In pursuit of lower bit error rate (BER), this paper based on pilot signals TDD LTE system on the uplink channel estimation algorithm. Use LS algorithm, MMSE algorithm and svd algorithm. Based on these three improved svd algorithm, it gave the simulation results.


2014 ◽  
Vol 1049-1050 ◽  
pp. 1906-1910
Author(s):  
Yong Wang ◽  
Pan Fei Wu ◽  
Guo Qing Xiong

The long term evolution (LTE) system is a high data rate transmission system. And the channel estimation is critical to it. In this paper, a novel channel estimator on the basis of Discrete Cosine Transform (DCT) method is presented for LTE. It can mitigate the aliasing error caused by spectral leakage well and is applicable for non-integer sampled channel because DCT can reduce the high frequency component. Its performance is much better than LS method and close to LMMSE method, and the complexity is much simpler than LMMSE. The simulation results show that the DCT-based method is superior to the traditional channel estimation algorithm in the multi-path Rayleigh fading channel which is a available and effective channel estimation method.


Data Mining ◽  
2013 ◽  
pp. 336-365
Author(s):  
Bing He ◽  
Bin Xie ◽  
Sanjuli Agrawal ◽  
David Zhao ◽  
Ranga Reddy

With the ever growing demand on high throughput for mobile users, 3G cellular networks are limited in their network capacity for offering high data services to a large number of users. Consequently, many Internet services such as on-demand video and mobile TV are hard to be satisfactorily supported by the current 3G cellular networks. 3GPP Long Term Evolution (LTE) is a recently proposed 4G standard, representing a significant advance of 3G cellular technology. Attractively, LTE would offer an uplink data speed up to 50 Mbps and a downlink speed up to 100 Mbps for various services such as traditional voice, high-speed data, multimedia unicast, and multimedia broadcasting. In such a short time, it has been broadly accepted by major wireless vendors such as Verizon-Vodafone, AT&T, NTT-Docomo, KDDI, T-Mobile, and China Mobile. In order for high data link speed, LTE adapts new technologies that are new to 3G network such as Orthogonal Frequency Division Multiplexing (OFDM) and Multiple-Input Multiple-Output (MIMO). MIMO allows the use of more than one antenna at the transmitter and receiver for higher data transmission. The LTE bandwidth can be scalable from 1.25 to 20 MHz, satisfying the need of different network operators that may have different bandwidth allocations for services, based on its managed spectrum. In this chapter, we discuss the major advance of the LTE and its recent research efforts in improving its performance. Our illustration of LTE is comprehensive, spanning from the LTE physical layer to link layer. In addition, the LTE security is also discussed.


2018 ◽  
Vol 2018 ◽  
pp. 1-6
Author(s):  
Xianwen He ◽  
Gaoqi Dou ◽  
Jun Gao

For the OFDM-based Amplify-and-Forward cooperative system, a novel relay-superimposed pilot strategy is proposed, where the source pilot symbols are frequency division multiplexed to estimate the cascaded channel while relay pilot sequence is superimposed onto the top of the cooperative data stream for second-hop channel estimation. This method avoids the loss of data rate for additional pilot subcarriers but results in the interference of unknown cooperative data. To remove the interference of cooperative data during the estimation of second-hop channel, the Cooperative Interference Cancelation scheme assisted by cooperative data from direct link is proposed. We derive the approximated lower bound for the MSE of second-hop channel estimation. Simulation results are presented to validate the performance of the proposed schemes.


2017 ◽  
Vol 67 (5) ◽  
pp. 581
Author(s):  
Sidharth Shukla ◽  
Vimal Bhatia

<p>Wireless mesh networks (WMN) are the networks of future and can operate on multiple protocols ranging from WiFi, WiMax to long term evolution (LTE). As a recent trend defence networks are incorporating off-the-shelf, state of the art commercial protocols to enhance the capability of their networks. LTE is one such commercially available protocol which is easy to deploy and provide high data rate which can be ideally implemented in WMN for defence networks. To enable these high data rate services LTE-based defence mesh networks (DMN) are the requirement of the day and future. However, LTE-based DMN are prone to congestion at times of active operations or full-fledged war. The congestion scenarios may lead to LTE packet loss. Hence, it is pertinent that these networks amalgamate information grooming algorithms to alleviate the throughput of the network in peak hour conditions. An efficient priority scheduling algorithm based on class of service prioritisation, data rate consumption and location of origin of traffic in the DMN is proposed. The simulations demonstrate that by incorporating the proposed priority scheduling algorithm, the overall packet loss of priority packets in the DMN reduces substantially.</p>


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