检索结果-内蒙古大学图书馆

low-complexity method for primary synchronisation in the third generation partnership project long term evolution downlink system

引用

IET COMMUNICATIONS 2016年第10期10卷 1229-1235页

作者： Jabbarvaziri, Faramarz Alizadeh, Mostafa Mohammadi, Abbas Abdipour, Abdolali Amirkabir Univ Technol Dept Elect Engn Tehran Iran

In this study, the authors propose a low-complexity method for symbol synchronisation in the third generation partnership project long term evolution (LTE) downlink system. The authors introduce the lowest sampling frequency of a receiver for synchronisation purposes. Using a low sampling frequency at the receiver means that the digital signal is decimated and a lower number of processing samples is needed. This results in reducing the computational complexity. It is also shown that this advantage comes at the cost of signal-to-noise ratio degradation and insertion of a systematic error in synchronisation that can be avoided by choosing a proper decimation factor. A thorough analysis is also conducted for all possible sampling frequencies that reduce the computational complexity of LTE cell search. To show the validity of the authors' method, they implemented an LTE primary synchroniser in C++ using GNU Radio libraries and prepared a software-based radio modem, tested in different conditions. Some Monte-Carlo simulations are carried out to compare the proposed method with other low-complexity methods. These comparisons show the suggested method is faster than available techniques in literatures.

关键词： 3G mobile communication Long Term Evolution synchronisation software radio Monte Carlo methods signal sampling radio receivers search problems low-complexity method primary synchronisation Third Generation Partnership Project Long Term Evolution downlink system 3GPP LTE downlink system symbol synchronisation low sampling frequency digital signal decimation LTE cell search C++ GNU Radio libraries software-based radio modem Monte-Carlo simulations

来源：评论

学校读者我要写书评

暂无评论

A low-complexity method to Compensate IQ-Imbalance and Phase Noise in MIMO-OFDM Systems

A Low-Complexity Method to Compensate IQ-Imbalance and Phase...

引用

54th Annual IEEE Global Telecommunications Conference (GLOBECOM)

作者： Jnawali, Shashwat Beygi, Sajjad Bahrami, Hamid Reza Univ Akron Dept Elect & Comp Engn Akron OH 44325 USA

ISBN: (纸本)9781424492688

The degrading effect of RF impairments on the performance of wireless communication systems is more pronounced in MIMO-OFDM transmission. Two of the most common impairments that significantly limit the performance of MIMO-OFDM transceivers are IQ-imbalance and phase noise. low-complexity estimation and compensation techniques that can jointly remove the effect of these impairments are highly desirable. In this paper, we propose a simple joint estimation and compensation technique to estimate channel, phase noise and IQ-imbalance parameters in MIMO-OFDM systems under multipath slow fading channels. A subcarrier multiplexed preamble structure to estimate the channel and impairment parameters with minimum overhead is introduced and used in the estimation of IQ-imbalance parameters as well as the initial estimation of effective channel matrix including common phase error (CPE). We then use a novel tracking method based on the second order statistics of the inter-carrier interference (ICI) and noise to update the effective channel matrix throughout an OFDM frame. Simulation results for a variety of scenarios show that the proposed low-complexity estimation and compensation technique can efficiently improve the performance of MIMO-OFDM systems in terms of bit-error-rate (BER).

关键词： Channel estimation Estimation IQ-imbalance compensation IQ-imbalance parameter estimation MIMO communication MIMO-OFDM transceiver OFDM OFDM modulation Phase noise RF impairment Receivers Training Vectors bit-error-rate channel estimation channel estimation channel matrix common phase error communication complexity compensation technique degrading effect error statistics fading channels impairment parameter intercarrier interference intercarrier interference joint estimation low-complexity estimation low-complexity method multipath slow fading channel phase noise estimation radio transceivers radiocommunication second order statistics subcarrier multiplexed preamble structure tracking tracking method wireless communication system

来源：评论

学校读者我要写书评

暂无评论

low-complexity methods for joint delay and Doppler estimation of unknown wideband signals

引用

IET RADAR SONAR AND NAVIGATION 2018年第4期12卷 398-406页

作者： Xiao, Xuebing Guo, Fucheng Feng, Daowang Natl Univ Def Technol Sch Elect Sci Changsha 410073 Hunan Peoples R China

A joint time delay and Doppler shift estimation of unknown wideband signals is studied in the sense that the variation of time delay over time and the migration of Doppler shift over signal frequency cannot be neglected. By partitioning the received signals into short time segments, a novel wideband signal model is proposed. Based on this model, the maximum likelihood estimate (MLE) of the time delay at the starting point of observation and the Doppler shift at the signal carrier frequency is derived. With well compensation of the migrations of these parameters, the MLE derived could achieve higher estimation accuracy. To lower the computational complexity, a fast estimation algorithm based on the Keystone transform is also presented. After correcting the migrations through the Keystone transform, successive one-dimensional Fourier transform, instead of two-dimensional grids search, is used to achieve coherent processing of the received signals. The Cramer-Rao lower bound analysis for wideband cases is presented and the computational complexity of the proposed algorithms is analysed. Simulation results demonstrate the superiority of the proposed methods for wideband cases.

关键词： Doppler shift maximum likelihood estimation compensation computational complexity Fourier transforms signal processing low-complexity method unknown wideband signal model joint time delay Doppler shift estimation maximum likelihood estimation MLE signal carrier frequency compensation computational complexity fast estimation algorithm keystone transform successive one-dimensional Fourier transform two-dimensional grid search Cramer-Rao lower bound analysis

来源：评论

学校读者我要写书评

暂无评论

A digital phase-based on-fly offset compensation method for decision feedback equalisers

引用

IET CIRCUITS DEVICES & SYSTEMS 2021年第4期15卷 297-309页

作者： Amaya, Andres Ardila, Javier Roa, Elkim Univ Ind Santander Sch Elect Engn Bucaramanga Colombia

A low-complexity method to reduce the offset voltage of dynamic comparators employed as samplers in decision feedback equalisers (DFE) is introduced. The authors propose the phase-domain offset reduction technique (PORT), which leverages an all-digital phase estimation of output data for offset compensation, without setting the comparator input to a common-mode voltage (V-CM). While traditional techniques might break the data link for offset adjustment, the proposed technique allows calibrating the comparator on-the-fly. Measurements from a 26-dB-loss on-chip emulated channel with chip-scope capability validates PORT through eye-diagrams at sampler input. A prototype was implemented in a TSMC 130 nm 1.2 V process, and experimental results show the possibility of extending PORT to state-of-the-art technology nodes for multi-gigabit operation.

关键词： on-chip emulated channel offset adjustment comparator on-the-fly low-complexity method comparator input TSMC process data link digital phase-based on-fly offset compensation method common-mode voltage calibration phase estimation offset voltage chip-scope capability loss 26 dB phase-domain offset reduction technique comparators (circuits) size 130 nm all-digital phase estimation output data sampler input PORT through eye-diagrams voltage 1.2 V dynamic comparators decision feedback equalisers

来源：评论

学校读者我要写书评

暂无评论

General method to mitigate the continuous wave interference and narrowband interference for GNSS receivers

引用

IET RADAR SONAR AND NAVIGATION 2020年第9期14卷 1430-1435页

作者： Lv, Qingshui Qin, Honglei Beihang Univ Sch Elect & Informat Engn Beijing Peoples R China

A low-complexity method based on the second-order direct infinite impulse response (IIR) notch and its cascaded form for global navigation satellite systems (GNSSs) is proposed to mitigate the continuous wave interference (CWI) and narrowband interference (NI) as well as their mixed interference. The number of the cascaded stages is selected by the bandwidth of NI as well as that of the second-order direct IIR notch. The parameters of the second-order direct IIR notch and the bandwidth of NI are determined by the fast Fourier transform. To evaluate the performance of the proposed method, the authors conduct the simulation experiment and real-data experiment. In each experiment, the CWI scenario, the NI scenario and the mixed interference of CWI and NI scenarios are verified. The results of experiments depict the effectiveness of the introduced method.

关键词： satellite navigation fast Fourier transforms IIR filters notch filters interference suppression computational complexity continuous wave interference narrowband interference mixed interference second-order direct IIR notch low-complexity method global navigation satellite systems cascaded stages GNSS receivers interference mitigation CWI mitigation NI mitigation fast Fourier transform performance evaluation

来源：评论

学校读者我要写书评

暂无评论

Simplification of strip-wise algorithms applied for two-dimensional intersymbol interference detection

引用

IET COMMUNICATIONS 2014年第2期8卷 242-249页

作者： Lee, Chang-Ming Wu, Tsung-Che Lin, Jian-Ren Natl Chung Cheng Univ Dept Commun Engn Chiayi 621 Taiwan

With the development of the high-speed communication channel or high-capacity storage device, the intersymbol interference (ISI) occurs more frequently in the condensed data. The traditional Bahl – Cocke – Jelineu – Raviv (BCJR) method is capable of solving the two-dimensional (2D) symbol influence problem with extremely high cost. By analysing the complexity in terms of branch, state and path in the 2D trellis-based ISI detection, the authors verify that the system complexity is mainly dominated by the window size. To reduce the detection complexity, the conventional simplifications are applied in the 2D strip-wise ISI detection. In addition, a two-phase strip-wise detection is proposed to achieve a lower complexity than that of the conventional simplifications. In this system, the first detector can be realised by a low-complexity method (like the hard detection or Viterbi algorithm) to provide the mask shrinking with predicted data. After reducing the mask size, the second detector can detect the main portion of ISI by the trellis-based detection (like BCJR algorithm) with a small mask. Under the similar detection performance, the proposed scheme can achieve more than 91.76% saving in the metric computation compared with the 5 × 3-window IRCSDFA (iterative row–column soft-decision feedback algorithm) simplified by the M -algorithm with M = 8.

关键词： intersymbol interference iterative methods wireless channels strip-wise algorithms two-dimensional intersymbol interference detection high-speed communication channel high-capacity storage device BCJR method 2D intersymbol interference detection 2D trellis-based ISI detection 2D strip-wise ISI detection two-phase strip-wise detection low-complexity method IRCSDFA iterative row-column soft-decision feedback algorithm M-algorithm

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：