Time synchronization algorithms for IEEE 802.11 OFDM systems

Xiao, Pei; Cowan, C.F.N.; Ratnarajah, Tharmalingam; Fagan, Ailís

doi:10.1049/cp.2009.1947

Cited by 7 publications

(5 citation statements)

References 8 publications

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“…There are several algorithms to perform OFDM package detection using the metric signal [21], [27], [28], [29]. This paper presents an improved variant of the threshold-based method [27], which obtains a better position of the maximum value of the metric.…”

Section: ) Mnc Methodsmentioning

confidence: 99%

“…where k indicates the index of each sub-carrier, N FFT is the size of samples that compose the FFT window, and θ represents the number of samples advanced due to the time offset [21]. Which implies that the phase offset is not constant for each sub-carrier, and depends of the position of each one in the window.…”

Section: B Time Offset and Phase Offsetmentioning

confidence: 99%

“…The time synchronization process at the receiver can be considered as the detection of the start of an OFDM package. The key to this stage is based on three fundamental concepts: auto-correlation, cross-correlation and metric [11], [12], [13], [21], [23], [26].…”

Section: Proposed Time Synchronization Techniquementioning

confidence: 99%

“…The performance of the OFDM system depends on the accuracy of the time synchronization, being a fundamental part of the system. In general, time synchronization has two stages: coarse synchronization and fine synchronization [10], [11], [21], [23]. The coarse synchronization is used to estimate the start of an OFDM package.…”

Section: Proposed Time Synchronization Techniquementioning

confidence: 99%

“…The main goal of coarse synchronization is the detection of the start of OFDM packages. For this purpose, training sequences are used at the beginning of each package [21], [23]. The proposed technique uses a modified variant of these sequences from the IEEE Std 802.11 ™ -2016 [25].…”

Section: A Coarse Synchronizationmentioning

confidence: 99%

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Time Synchronization Technique Hardware Implementation for OFDM Systems With Hermitian Symmetry for VLC Applications

2023

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The main contribution of this work is the proposal and hardware implementation of an algorithm for the time synchronization of orthogonal frequency division multiplexing (OFDM) modulation with Hermitian symmetry for visible light communications (VLC) systems, using only the real component of the transmitted signal. OFDM systems with Hermitian Symmetry are able to satisfy the high data rates demanded by many VLC systems, as well as deal with inter-symbol interference (ISI). However, these systems are characterized by being very vulnerable to synchronization problems in both time and frequency. Time synchronization being the most critical. In this paper, a novel time synchronization technique for OFDM systems with Hermitian Symmetry is proposed. This technique is based on the inclusion of a post-FFT synchronization stage to achieve time synchronization with one-sample precision. For this purpose, the relationship that exists between an offset in the frequency domain with an offset in the time domain is used, and with this information the correction of the frequency offset from the time domain is performed. An original and novel algorithm has been designed and implemented in hardware, which uses the cyclic prefix (CP) elimination stage to perform the time correction. The performance validation of the proposed technique is done with the implementation, using the ZYBO ™ development board, of a complete OFDM system applied to a real VLC system.INDEX TERMS Visible light communication (VLC), orthogonal frequency division multiplexing (OFDM), time synchronization, Hermitian symmetry.

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Section: ) Mnc Methodsmentioning

confidence: 99%

Section: B Time Offset and Phase Offsetmentioning

confidence: 99%