An improved performance OFDM channel estimation using pilot-symbol-aided technique

العناوين الأخرى

تحسين جودة تقييم القناة في نظام التقسيم الترددي المتعدد التعامدي باستخدام الرموز التجريبية

مقدم أطروحة جامعية

al-Tarawinah, Anwar Yusuf

مشرف أطروحة جامعية

al-Jaafirah, Yusuf Ghazi

أعضاء اللجنة

al-Matarnah, Asir Muhammad Zayid
al-Zubi, Khalid Qasim
Siyam, Muhammad Zakariyya

الجامعة

جامعة مؤتة

الكلية

كلية الهندسة

القسم الأكاديمي

قسم الهندسة الكهربائية

دولة الجامعة

الأردن

الدرجة العلمية

ماجستير

تاريخ الدرجة العلمية

2015

الملخص الإنجليزي

Orthogonal Frequency Division Multiplexing (OFDM) provides an effective and low complexity means of eliminating inter-symbol interference over frequency selective fading channels.

OFDM received a lot of interest in mobile communication research, as radio channel is usually a time variant and frequency selective.

The objective of this thesis is to improve channel estimation accuracy in OFDM system, because channel state information is needed for signal detection at the receiver, consequently, its accuracy affects the overall performance of the system.

In practice, CSI can be reliably estimated at the receiver by transmitting pilot symbols along with data symbols.

Pilot symbol assisted channel estimation is especially attractive for wireless channel, where the channel is time-varying.

In this thesis, various efficient pilot assisted channel estimation schemes were investigated and compared for OFDM system.

Two major types of pilot arrangements, namely, block type and comb-type have been focused on this thesis.

Block type pilot subcarriers, is particularly suitable for slow-fading radio channels, whereas, comb-type pilots arrangement exhibit better resistance to fast fading channels.

The choice of channel estimation is of fundamental importance in OFDM receiver designs, which further involves a trade-off between complexity and estimation accuracy.

There are several methods for the estimation of the channel, namely; Least Square (LS), Minimum Mean Square Error and Modified Minimum Mean Square Error (LMMSE).

The mathematical model for each of these estimators was derived and their performance was investigated on MATLAB.

The results showed clearly that LS algorithm gives less complexity compared with MMSE and LMMSE but LMMSE algorithm provides comparatively better results.

A one dimensional (1-D) and two dimensional (2-D) pilot symbol assisted channel estimators for OFDM systems are simulated also for comparison purpose, The performance of the 2-D channel estimator is much better than that of the 1-D channel estimator of Mean Square Error (MSE) as a function of signal-to-noise ratio (SNR).

Results showed that as the number of pilot symbols increases, the MSE decreases (i.e, improved performance).

التخصصات الرئيسية

هندسة الاتصالات

عدد الصفحات

54

قائمة المحتويات

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-677665