scholarly journals Non-perfect channel estimation in OFDM-MIMO-based underwater communication

2009 ◽  
Author(s):  
Knut Grythe ◽  
Jan Erik Hakegard
Keyword(s):  
Channel Estimation ◽  
Underwater Communication ◽  
Perfect Channel

Frequency-domain channel estimation for nonlinear multicarrier underwater communication systems

2010 ◽  
Author(s):  
Ching-Hsiang Tseng ◽  
Chin-Feng Lin ◽  
Fu-Sheng Lu ◽  
Hsien-Sen Hung ◽  
Tzong-Dar Wu ◽  
...  
Keyword(s):  
Channel Estimation ◽  
Frequency Domain ◽  
Communication Systems ◽  
Underwater Communication

Effect of Channel Estimation Error on Coordinated Small-Cells with Block Diagonalization

2014 ◽  
Vol 556-562 ◽  
pp. 4501-4504
Author(s):  
Soo Young Shin ◽  
Toha Ardi Nugraha
Keyword(s):  
Channel Estimation ◽  
Channel State Information ◽  
Cooperative Communication ◽  
Estimation Error ◽  
Small Cells ◽  
Block Diagonalization ◽  
Channel State ◽  
State Information ◽  
The Real ◽  
Perfect Channel

This paper investigates the implementation of cooperative communication in small-cells network. Cooperative communication is some cells that in a network can work together, ex. joint transmit power and exchange resource allocation among them. Therefore, cooperative small-cells can be possible to add more multiple input multiple output (MIMO) antennas. But, channel state information (CSI) is required. In practice, perfect channel state information may not be perfect due to the real condition of the real environment such as delay, error, and etc. This paper illustrates cooperative small-cells under error model on the channel estimation. Our propose system is combined by implementing block diagonalization pre-coding and power allocation based on water-filling algorithm. As investigated by simulation results, our proposed coordinated small-cells showed good performances compare to previous algorithm either with perfect channel or with the error channel estimation.

scholarly journals Design and Development of Novel Channel estimation method for OFDM based Underwater communication

2021 ◽  
Author(s):  
Asha M ◽  
T P Surekha
Keyword(s):  
Channel Estimation ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Multipath Propagation ◽  
Research Work ◽  
Estimation Method ◽  
Underwater Communication ◽  
Frequency Division ◽  
Transmission Method ◽  
Shift Keying

Abstract The ocean is a constantly changing environment whose properties are still great Challenges to Developing Effective Underwater Wireless Communication represent. The high absorption of electromagnetic and optical signals in the water limits this Use and development of underwater electromagnetic communication systems. A possible approach to wireless underwater communication over longer distances (> 100m), offers acoustic signal transmission, modulation methods such as frequency shift keying are also used (FSK) and phase-shift keying (PSK) are used. In many areas the orthogonal frequency division multiplex method (Orthogonal Frequency Division Multiplexing, OFDM) is enforced for high data rates. It offers a multi-carrier transmission method Benefits in treating multipath propagation, nevertheless achieves a bandwidth efficiency similar to that of corresponding single-carrier processes. In recent studies, the OFDM methods are adopted for underwater communication. However the real time implementation is becoming a challenging part. The channel estimation plays vital role in underwater communication. In this research work, the novel sparse channel estimation in OFDM based underwater communication is proposed for long distances. The proposed algorithms are developed in fixed point manner which can be implemented in FPGA. The BER values are estimated for proposed algorithm and validated with the conventional algorithms. The proposed algorithms exhibits better results compared with the conventional algorithms.

scholarly journals Pilot-Based Adaptive Channel Estimation for Underwater Spatial Modulation Technologies

Symmetry ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 711 ◽  
Author(s):  
Naveed Ur Rehman Junejo ◽  
Hamada Esmaiel ◽  
Haixin Sun ◽  
Zeyad A. H. Qasem ◽  
Junfeng Wang
Keyword(s):  
Channel Estimation ◽  
Communication Systems ◽  
Estimation Method ◽  
Spatial Modulation ◽  
Mimo Channel ◽  
Underwater Acoustic ◽  
Mimo Communication ◽  
Adaptive Channel Estimation ◽  
Perfect Channel ◽  
Ber Performance

Spatial Modulation Technologies (SMTs) are schemes that reduce inter-carrier interference (ICI), inter-channel interference, inter-antenna synchronization (IAS), and system complexity for multiple-input multiple-output (MIMO) communication systems. Moreover, high spectral and energy efficiency have rendered SMTs attractive to underwater acoustic (UWA) MIMO communication systems. Consequently, this paper focuses on SMTs such as spatial modulation (SM), generalized spatial modulation (GSM), and fully generalized spatial modulation (FGSM) in which one constant number and one multiple number of antennas are active to transmit data symbols in any time interval for underwater acoustic communication (UWAC). In SMTs, the receiver requires perfect channel state information (P-CSI) for accurate data detection. However, it is impractical that the perfect channel knowledge is available at the receiver. Therefore, channel estimation is of critical importance to obtain the CSI. This paper proposes the pilot-based recursive least-square (RLS) adaptive channel estimation method over the underwater time-varying MIMO channel. Furthermore, maximum likelihood (ML) decoder is used to detect the transmitted data and antennas indices from the received signal and the estimated UWA-MIMO channel. The numerical computation of mean square error (MSE) and bit error rate (BER) performance are computed for different SMTs like SM, GSM and FSGM using Monte Carlo iterations. Simulation results demonstrate that the RLS channel estimation method achieves the nearly same BER performance as P-CSI.

Performance indicator for DMT systems with non perfect channel estimation

2006 ◽  
Vol 17 (5) ◽  
pp. 591-597 ◽  
Author(s):  
D. Bueche ◽  
P. Corlay ◽  
M. G. Gazalet ◽  
F. X. Coudoux ◽  
M. Slachciak
Keyword(s):  
Channel Estimation ◽  
Performance Indicator ◽  
Perfect Channel

scholarly journals On Channel Codes for Short Underwater Messages

Information ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 58 ◽  
Author(s):  
Melanie Falk ◽  
Gerhard Bauch ◽  
Ivor Nissen
Keyword(s):  
Channel Estimation ◽  
Error Correcting Codes ◽  
Polar Codes ◽  
Underwater Communication ◽  
Alphabet Size ◽  
Reliable Transmission ◽  
Channel Codes ◽  
Channel Estimation And Equalization

Acoustic underwater communication is a challenging task. For a reliable transmission, not only good channel estimation and equalization, but also strong error correcting codes are needed. In this paper, we present the results of the coding competition “Wanted: Best channel codes for short underwater messages” as well as our own findings on the influence of the modulation alphabet size in the example of non-binary polar codes. Furthermore, the proposals of the competition are compared to other commonly used channel codes.

Perfect Channel Estimation of LTE Downlink Performance under HST Condition

2021 ◽  
Author(s):  
Fatima F. Al-Azzawi ◽  
Zina A. Lateef ◽  
Ali M. Mozan
Keyword(s):  
Channel Estimation ◽  
Perfect Channel
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