TIMING SYNCHRONIZATION IN MIMO-OFDM SYSTEMS A thesis presented to the faculty of the Graduate School of Western Carolina University in partial fulfillment of the requirements for the degree of Master of Science in Technology. By (original) (raw)

DOI: 10.5121/ijit.2014.3201 1 Study of Timing Synchronization in MIMO- OFDM Systems Using DVB-T

2016

OFDM (Orthogonal Frequency Division Multiplexing)provides the promising physical layer for 4G and 3GPP LTE Systems in terms of efficient use of bandwidth and data rates. This paper highlights the implementation of OFDM in Digital Video Broadcasting-Terrestrial (DVB-T). It mainly focuses on the timing offset problem present in OFDM systems and its proposed solution using Cyclic Prefix (CP) as a modified SC (Schmidl and COX) algorithm. It also highlights the timing synchronization as well as performance comparison through bit error rate. Synchronization issues in OFDM are important and can lead to information loss if not properly addressed. Simulations were performed to implement DVB-T system and to compare different synchronization methods under certain distribution model.

Study of Timing Synchronization in MIMOOFDM Systems Using DVB-T

International Journal on Information Theory, 2014

Timing synchronization in MIMO-OFDM systems

2013

To my parents Mr. & Mrs. Michael Mehboob and my love Merab Mushfiq ACKNOWLEDGEMENTS One cannot even imagine the power of the God that guides us all and we cannot succeed without Him. I would like to acknowledge my deepest gratitude to GOD ALMIGHTY who blessed me with the opportunity to complete this thesis project. The completion of this research project is never complete without thanking those people who helped me to complete it. First of all I thank Dr. James Zhang my major advisor for his guidance, support, patience, trust and time during the completion of research. Without his efforts and support I would not be able to complete my research. I would like to thank Dr. Weiguo Yang and Dr. Yeqin Huang for serving as my thesis committee members. I also want to thank Dr. Aaron Ball for his help and encouragement during the research. In the end, I wish to thank the staff members of Engineering and Technology department and Kimmel School for providing the required facilities to perform the research.

A Review on Timing & Synchronization Technique in OFDM

International Journal of Science and Research (IJSR), 2017

The aim of this paper is to survey and compare previous methods for Data-aided timing and frequency synchronization of OFDM System.Synchronization has been one of the crucial research topics in orthogonal frequency division multiplexing (OFDM) system because of its sensitivity to the timing and frequency errors [1]. To guarantee the fast and accurate data transmission, the Inter Symbol Interference (ISI) and Inter Carrier Interference (ICI) caused in the transmission have to be eliminated as much as possible.ORTHOGONAL frequency-division multiplexing(OFDM) has been of major interest for both wireline-based and wireless applications [1]-[3] due to its highdata rate transmission capability and its robustness to multipathdelay spread. However, OFDM systems are much more sensitive to synchronization errors than single carrier systems [4],[5]. This paper summarizes various methods to cater this synchronization problem.

Review on Comparison of Different OFDM Symbol Timing Synchronization Algorithms

Orthogonal Frequency Division Multiplexing (OFDM) is the key technology for 4G and 3GPP LTE systems due to its highly efficient bandwidth and multi carrier modulation. The benefit of using OFDM is that it avoids ISI (Inter Symbol Interference) and ICI (Inter carrier Interference) by using timing synchronization technique. For this the symbols must be in properly synchronized form. It also have Higher transmission rate. So SC (Schmidl and Cox) algorithm is designed, It provides timing synchronization and lowers BER( Bit Error Rate). Based on the research of Schmidl & Cox, Minn and Bhargava and Park et al. synchronization algorithm, this paper proposed a comparison on these three timing synchronization algorithms

Time and Frequency Synchronization in OFDM System

2014

Orthogonal frequency division multiplexing (OFDM) is one of the multicarrier modulation techniques, which transmits data in very high rate and efficiently mitigates the effects of multipath distortions as well as loss in bandwidth efficiency. However, OFDM systems are very sensitive towards synchronization error. Synchronization of an OFDM signal is required to find the symbol timing and carrier frequency offset (CFO). Before demodulation of subcarriers, either from explicit training data or using cyclic prefix of the OFDM signal we can get synchronization at receiver. After demodulation of the OFDM subcarriers, information about the synchronization can be obtained from training symbols embedded into the regular data symbol pattern. The estimation of synchronization error can be performed depending on the type of the training data. In this paper, it is focused on preamble based training data following IEEE802.11a preamble structure of the WLAN system and cyclic prefix based training...

A Novel Timing Synchronization Method for MIMO-OFDM Systems

International Journal on Advances in Telecommunications, 2014

To increase the throughput of transmission systems, MIMO-OFDM technology enables better transmission rate and improves the reception. The synchronization between the transmitter and the receiver has become a big challenge. A bad timing synchronization causes the loss of a lot of information in a MIMO-OFDM system. In this paper, a novel timing synchronization method is proposed for a MIMO-OFDM systems with Nt transmit antennas and Nr receive antennas. The proposed method is based on transmit an orthogonal CAZAC sequences over different transmit antennas [1]. Simulations results show that the proposed solution presents a good performance at a low SNR (Signal to Noise Ratio) in AWGN and multipath fading Rayleigh channels, where Doppler Effect is not considered for current simulations. Furthermore, this method can be implemented for MIMO-OFDM system up to 8 × 8 as well. In the proposed method, the coarse and fine timing synchronization are done at the same time at each receive antenna due to the different training sequences transmitted over different transmit antennas.

A Novel Timing Synchronization Method for OFDM Systems

IEEE Communications Letters, 2000

In this letter, a novel timing offset estimation method is presented for orthogonal frequency division multiplexing (OFDM) systems. The proposed method is developed on the basis of the cyclic structure of OFDM symbol and uses a new noise subspace based metric to estimate the timing offset. Simulation results show that the proposed method has a significantly higher probability of correct estimation of the timing offset than the other methods in multipath channels.

New Algorithm for Time and Frequency Synchronization in MIMO-OFDM Systems

Wireless Personal Communications, 2017

This paper addresses the problem of time and frequency synchronization in MIMO-OFDM systems, which are extremely sensitive to these errors. A preamble based algorithm is proposed for the estimation of synchronization errors. Product of autocorrelation function and cross correlation function is used for symbol timing offset estimation which reduces the uncertainty in timing estimation due to timing metric plateau. Phase difference between two identical parts of the preamble is used for carrier frequency offset estimation. Simulation results are presented to validate the performance of the algorithm.

A Novel Timing and Frequency Synchronization Technology for OFDM System

Due to its high spectrum efficiency and good ability in coping with multi-path fading, orthogonal frequency division multiplexing (OFDM) technology has attracted considerable attention from researchers. However, OFDM system is very sensitive to symbol timing offset and carrier frequency offset, so accurate timing synchronization and frequency synchronization are necessary to OFDM system. This paper discusses on OFDM synchronization technology based on training symbol. OFDM synchronization algorithms based on training symbol are investigated, and two algorithms are proposed. An improved algorithm is proposed aimed at resolving training symbol redundancy and timing metric plateau in Schmidl algorithm. The training symbol in this algorithm is conjugated symmetrical and repeated. The timing metric has a sharp peak and eliminates the plateau. Both integral and fractional frequency offset estimation employ the same training symbol, and therefore the system overhead is saved and the complexity is degraded. The second algorithm proposed in this paper does not just improve symbol timing method or frequency offset estimation method. It is a complete set of solution project of OFDM synchronization. A new training symbol with special structure is designed, and a new joint symbol timing and frequency synchronization algorithm is presented based on this symbol. New frequency offset estimation algorithms are characteristic of large estimation range and high accuracy. At the same time, timing synchronization can produce a sharp peak, through which we can find where the OFDM symbol starts. The simulation results show that the performance of the synchronization algorithms proposed here is better than that of conventional methods.

TIMING SYNCHRONIZATION IN MIMO-OFDM SYSTEMS A thesis presented to the faculty of the Graduate School of Western Carolina University in partial fulfillment of the requirements for the degree of Master of Science in Technology. By (original) (raw)

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