Performance of OFDM in Time Selective Multipath Fading Channel in 4G Systems

Dixit, Saurabh; Katiyar, Himanshu

doi:10.1109/csnt.2015.107

Cited by 21 publications

(8 citation statements)

References 12 publications

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“…The principle of operation OFDM technology depends on the fragmentation of the signal to be sent into several parts. Each part is sent on a narrow frequency channel called the carrier so that each carrier is orthogonal to the neighbouring carriers on its two ends; for example, when the carrier has the greatest value, the adjacent carriers have a zero value as shown Fig 2 . [5], [6]. Although 5 th generation technologies have become faster than 4 th generation technologies in transmitting data, they are still limited to use due to the high prices of mobile phones that work with this technology [7], and some researchers claim there is a relationship between short frequencies of 5 th generation technologies and appearance of the Coronavirus (Covid 19) [ 8].…”

Section: Introductionmentioning

confidence: 99%

Implementation of LTE in Mosul city: problems and solution

Sadoon¹,

Ayoob²

2022

Proceedings of 2nd International Multi-Disciplinary Conference Theme: Integrated Sciences and Technologies, IMDC-IST 2021, 7-9

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The selection of cell tower locations is an essential step in designing any cellular system network. The sites are selecting according to the specifications of that system. In addition, each cellular system has optimal geographic locations appropriate to the frequency and design of that system. For example, the sites of the second-generation (2 nd G) system towers may not be compatible with the sites of the fourth generation (4 th G) system towers for long-term evaluations (LTE) technology in terms of design and location. However, most companies that provide cellular service choose the same locations as the 2 nd generation towers to prepare 4 th generation service to save operating and construction costs. After operating 4 th generation service in the same locations of the 2 nd generation towers in the city of Mosul, many problems appeared in the cellular coverage. In this paper, these problems are discussing and comparing with the results of the Atoll software. Methods have been proposing to solve these problems and improve cellular coverage by up to 7% of the area covered.

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Section: Introductionmentioning

confidence: 99%

Implementation of LTE in Mosul city: problems and solution

Sadoon¹,

Ayoob²

2022

Proceedings of 2nd International Multi-Disciplinary Conference Theme: Integrated Sciences and Technologies, IMDC-IST 2021, 7-9

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“…The increased demand for data rate and User Equipments (UE) restricted to a limited electromagnetic spectrum for wireless communications, make the project requirements along the evolution of the generations more challenging. Fourth generation (4G) networks have achieved a big success, due to their ability to provide high data rates for a large number of users using the Orthogonal Frequency Division Multiplexing (OFDM) modulation [1] [2].…”

Section: Introductionmentioning

confidence: 99%

Performance Evaluation of Low-Complexity Algorithms for Orthogonal Time-Frequency Space Modulation

Bandeira

Ruyet

Pischella

et al. 2020

JCIS

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Data transmission in wireless systems brings numerous challenges, especially when it involves propagating in a multipath scenario over rapidly time-varying channels. In this context, Orthogonal Time-Frequency Space (OTFS) modulation has been recently proposed to work with time-frequency selective channels with high Doppler. In this modulation, the symbols are first multiplexed in a delay-Doppler domain rather than in the time-frequency domain used by Orthogonal Frequency Division Multiplexing (OFDM). The studies point out advantages of OTFS performance over OFDM in many aspects, such as data rate increase in high mobility. Another advantage is the sparsity of the channel produced by OTFS that allows using lowcomplexity algorithms for the detection of the data. In this paper, the performance of OTFS modulation in a doubly dispersive channel is evaluated with several low-complexity variants of the message passing algorithm (MPA) in terms of complexity and Bit Error Rate (BER) performance. The results show that MPA and Approximate Message Passing simplified by Expectation Propagation (AMP-EP) algorithms achieve higher performance. However, when taking into account both complexity and BER performance, AMP simplified by First-Order (AMP-FO) achieves the best performance-complexity tradeoff.

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“…Initially, OFDM was proposed by Chang 1970 to mitigate the inter-symbol interference (ISI) and interchannel interference (ICI), where it was known as a digital modulation method [5]. The attribute of an OFDM and its utilization transform 3G to 4G in which application of multicarrier modulation (MCM) by means of 4G provides dual usages.…”

Section: Introductionmentioning

confidence: 99%

“…Firstly, it reduces the noise or interference in the receiver of MCM system in comparison to single carrier modulation (SCM). Secondly, it mitigates fading channel and impulse noise in the long symbol period in MCM [5].…”

Section: Introductionmentioning

confidence: 99%