In this contribution, we investigate the sensitivity of MC-CDMA systems to synchronisation errors. We show that the signal-tonoise ratio (SNR) of the MC-CDMA system at the input of the decision device in the presence of a carrier frequency offset or a clock frequency offset is a rapidly decreasing function of the number of carriers. For a maximal load, carrier phase jitter and timing jitter giv...

As it has already been revealed, the OFDM systems are very sensitive to the CFO. CFO is one of the most important drawbacks of the OFDM wireless systems. CFO destroys the orthogonality relationship between the subcarrier and creates ICI in OFDM systems. ICI can create frequency mismatched between the transmitter and receiver; this frequency mismatch can lead to the severe performance degradatio...

The authors consider a low-complexity technique for direct-sequence spread spectrum code acquisition. They present performance analysis in Rayleigh fading channels, and with carrier frequency offset in the receiver. They derive analytical expressions for acquisition probabilities, and use them to determine the mean and variance of the acquisition time. It is shown that acceptable performance ca...

In this contribution, we propose a variant of the MC-CDMA system that offers more flexibility than the traditional MC-CDMA system. We investigate the sensitivity of this flexible MC-CDMA system to some types of synchronisation errors. This flexible MC-CDMA system is not affected by a constant phase offset or a constant timing offset, as in the proposed flexible MC-CDMA system the carriers insid...

This paper presents an overview of the effect of synchronisation errors on MCCDMA performance in downlink communications. We distinguish two types of synchronisation errors: carrier phase errors and timing errors. We show that the MC-CDMA system is very sensitive to a carrier frequency offset or a clock frequency offset. For a maximal load, carrier phase jitter and timing jitter give rise to a ...

We introduce a blind algorithm for the joint estimation of s mbol timing and carrier frequency offset in pulse shaping 6FDM systems. The proposed estimator exploits the cyclostationarity of the received OFDM signal and can be seen as an extension of the Gini-Giannakis estimator (11 for single-carrier systems. An important feature of our method is the capability to perform a carrier frequency ac...

In this paper, a new time synchronization algorithm for OFDM systems with repetitive preamble is proposed. This algorithm makes use of coarse and fine time estimation; the fine time estimation is performed using a cross-correlation similar to previous proposals in the literature, whereas the coarse time estimation is made using a new metric and an iterative search of the last sample of the repe...

In this paper, we present a new class of blind cyclic-based estimators for carrier frequency offset and symbol-timing error estimation of orthogonal frequency-division multiplexing (OFDM) systems. The proposed approach exploits the properties of the cyclic prefix subset to reveal the synchronization parameters in the likelihood function of the received vector. In this paper, a new likelihood fu...

A joint frame synchronization and reversed spectrum signal differentiation method for DRM Plus digital broadcasting systems is proposed. The proposed scheme can detect the fast frame synchronization and determine whether normal spectrum signal or reversed spectrum signal without carrier frequency offset & sampling frequency offset compensation, enabling fast frame synchronization. The proposed ...

This paper derives new tracking results for adaptive filtering algorithms operating in the presence of two sources of nonstationarities: a carrier frequency offset and random variat.ions. Both impairments are common in digital communications due t,o variations in channel characteristics and to mismatches between transmitter and receiver carrier generators.