scholarly journals Improved Interference Cancelation Channel Estimation Method in OFDM/OQAM System

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Shangfei Qiu ◽  
Lunsheng Xue ◽  
Peng Wu
Keyword(s):  
Channel Estimation ◽  
Spectral Efficiency ◽  
Orthogonal Frequency Division Multiplexing ◽  
Estimation Method ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Estimation Performance ◽  
Interference Cancelation ◽  
Simulation Results ◽  
Method Show

To the significant amount of pilot overhead of the interference cancelation methods in orthogonal frequency division multiplexing (OFDM) based on offset quadrature amplitude modulation (OFDM/OQAM) system, we proposed an improved interference cancelation method (ICM) for OFDM/OQAM system in this paper. In this method, we use the auxiliary pilot (AP) to eliminate the influence of the intersymbol interference on channel estimation, which can reduce the pilot overhead of OFDM/OQAM system significantly. At the same time, to improve the channel estimation performance, we analyze the source of the intrinsic interference of system and its distribution in time and frequency domain, then, we reset the interference cancelation range of AP, which can cancel more intrinsic interference for OFDM/OQAM system. According to the results of performance analysis, compared to the conventional interference cancelation methods, the proposed method performs better in terms of energy efficiency and spectral efficiency. Also, the simulation results of the proposed method show that the proposed method can outperform traditional interference cancelation methods in channel estimation performance.

The Study of Interpolation Algorithms in OFDM Systems

2013 ◽  
Vol 321-324 ◽  
pp. 2837-2840
Author(s):  
Xi Jun Zhang ◽  
Jian Bin Xue ◽  
Ying Lin ◽  
Ji Ai He
Keyword(s):  
Channel Estimation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Ofdm System ◽  
Simulation Process ◽  
Interpolation Algorithms ◽  
Simulation Results

Orthogonal frequency division multiplexing (OFDM) is a kind of highly transmission technology. It has been taken more and more attention in many ways. In this paper it mainly discussed the simulation process and several interpolation algorithms in OFDM system. Using computer we simulate the interpolation algorithms in OFDM channel estimation. Through the simulation results we compare the advantage and disadvantage of the interpolation algorithms. At last we can use the conclusion to choose the correct interpolation algorithms in OFDM channel estimation.

scholarly journals Pilot Sequence Assisted Channel Estimation in MIMO/SIMO/SISO-OFDM Systems

2020 ◽  
Author(s):  
Xiao Zhou ◽  
Chengyou Wang ◽  
Qun Wu
Keyword(s):  
Channel Estimation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Estimation Method ◽  
High Order ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm System ◽  
Input Multiple Output ◽  
Mimo Ofdm ◽  
Single Input

Abstract For improving the communication system performance in multiple input multiple output- orthogonal frequency division multiplexing (MIMO-OFDM) system, single input multiple output-orthogonal frequency division multiplexing (SIMO-OFDM) system, single input single output-orthogonal frequency division multiplexing (SISO-OFDM) system, this paper introduces a pilot assisted channel estimation method. The proposed method is a combination of pilots and channel estimation based on known channel state information (CSI). First, the pilots are used to maintain the orthogonality characteristics of space time block coding (STBC). By designing the interference-free pilots we estimating the channel, and then with the pre-estimated channel characteristics data is decoded at the MIMO-OFDM system receiver. In this paper, we proposed four kinds of comb-type pilot sequences with interference-free pilots designing among consecutive subcarriers. The proposed pilot assisted channel estimation method in MIMO/SIMO/SISO-OFDM systems could be well adopted with different low and high order modulations. This flexible transmission mechanism can save pilot overhead and has strong anti-interference ability in dynamic channels. Moreover, high-order constellation modulation level will enhance the channel capacity in MIMO/SIMO/SISO-OFDM system. Therefore, it can be used as a candidate technology for 5G or 6G MIMO/SIMO/SISO-OFDM system.

scholarly journals Channel estimation of OFDM in C-band communication systems under different distribution conditions

2021 ◽  
Vol 23 (3) ◽  
pp. 1778
Author(s):  
Heba Abdul-Jaleel Al-Asady ◽  
Hassan Falah Fakhruldeen ◽  
Mustafa Qahtan Alsudani
Keyword(s):  
Fourier Transform ◽  
Channel Estimation ◽  
Fast Fourier Transform ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm System ◽  
High Data ◽  
High Efficient

<p>Orthogonal frequency division multiplexing (OFDM) is a transmission system that uses multiple orthogonal carriers that are sent out at the same time. OFDM is a technique for mobile and wireless communication that has high-efficient frequency utilization, high data-rate transmission, simple and efficient implementation using the fast Fourier transform (FFT) and the inverse fast Fourier transform (IFFT), and reduces inter symbol interference (ISI) by inserting cyclic prefix (CP). One of the most important approaches in an OFDM system is channel estimation. In this paper, the orthogonal frequency division multiplexing system with the Rayleigh channel module is analyzed for different areas. The proposed approach used large numbers of subcarriers to transmit the signals over 64-QAM modulation with pilot add channel estimation. The accuracy of the OFDM system is shown in the measuring of the relationships of peak power to the noise ratio and bit error rate.</p>

scholarly journals Iterative Channel Estimation Scheme for the WLAN Systems with the Multiple-Antenna Receivers

2012 ◽  
Vol 6-7 ◽  
pp. 871-875
Author(s):  
Zi Wei Zheng
Keyword(s):  
Fourier Transform ◽  
Channel Estimation ◽  
Fast Fourier Transform ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multipath Fading ◽  
Spectrum Efficiency ◽  
Frequency Division Multiplexing ◽  
Multiple Antenna ◽  
Frequency Division ◽  
Estimation Scheme

Alleviate the multipath delay spread and suitable for broadband transmission efficiency, orthogonal frequency division multiplexing wireless local area network (WLAN) is widely used to assist inverse fast Fourier transform and fast Fourier transform operation domain. Orthogonal frequency division multiplexing is a blow to the broadcast channel multipath fading and high data throughput, transmission, wireless fading channel method, which is widely used to support high performance bandwidth-efficient wireless multimedia services. Several times in the transmitter and receiver antenna technology allows data transfer rate and spectrum efficiency and the use of multiple transmit antennas and multiple receive antennas through spatial processing. High-precision channel estimation scheme is very important wideband multi-carrier orthogonal frequency complex WLAN systems use multiple antenna receiver based division of labor and the overall multi-carrier orthogonal frequency multiplexing division of performance-based WLAN system is to crucial antenna to receive the symbol error rate. In this article, the iterative channel estimation scheme proposed multi-carrier orthogonal frequency division multiplexed using multiple antennas receiver-based WLAN system.

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