The presence of residual carrier frequency offset (CFO) in an orthogonal frequency division multiplexing (OFDM) system leads to a loss of orthogonality between the subcarriers. This introduces inter-subcarrier interference and degrades the system performance significantly. In the literature, Liu and Tureli proposed a blind CFO estimation method based on the observation that in a typical OFDM sy...

We address the problem of nondata aided frequency offset estimation for noncircular transmissions over frequencyselective channels in a linear precoder-based communications context. Linear precoding is representative of a downlink direct-sequence code division multiple access (DS-CDMA) system or of an orthogonal frequency division multiplexing (OFDM) system. We observe that twice the frequency ...

Abstract—A novel preamble design is proposed for orthogonal frequency division multiplexing systems, which exploits the variable distance between a pair of training sequences for the transmission parameter signalling. Compared to the existing P1-symbol based preamble for the second generation digital terrestrial television broadcasting standard, the proposed design maintains the high performanc...

In this paper, estimation of carrier frequency offset (CFO) in orthogonal frequency division multiplexing (OFDM) systems with I/Q imbalance is studied. By exploiting the mirror spectrum induced by I/Q imbalance, we proposed a novel algorithm for blind CFO estimation without training sequences. Simulation results show that the proposed algorithm outperforms the existing one, which is well accept...

In this article, we develop a new subspace-based multiuser joint carrier frequency offset (CFO) and direction-ofarrival (DOA) estimation scheme for orthogonal frequency division multiple access uplink transmissions. We leverage multi-antenna at the receiver and consider that the signals transmitted by each user arrive at the receiving antenna array from multiple DOAs after bouncing from both su...

A new AFC algorithm is presented in this paper for correcting the sizable carrier frequency offset of a fully-digital MDPSK DSXDMA receiver, which explores the power degradation at the correlator output and has an acquisition range of twice the symbol rate. To achieve fast frequency acquisition, the momentum steepest descent method and modified S-curve are employed in the algorithm. The simplic...

Frequency synchronization is a critical requirement for single-carrier frequency division multiple-access (SC-FDMA) uplink transmissions. Based on the key observation that the received signal at the base station can be formulated as the parallel factor analysis model, we present a joint carrier frequency offset (CFO) estimation and compensation scheme for SC-FDMA uplink transmissions with inter...

We present a novel algorithm for estimating the Carrier Frequency Offset (CFO) in an OFDM receiver. The algorithm is based on locating the spectral minimas within null subcarriers embedded in the spectrum. This is done by using a scaled DFT algorithm to calculate the spectrum of the OFDM symbol around the null subcarrier, followed by averaging the absolute square of the amplitude. The method is...

Due to its high spectrum efficiency and good ability in coping with multi-path fading, orthogonal frequency division multiplexing (OFDM) technology has attracted considerable attention from researchers. However, OFDM system is very sensitive to symbol timing offset and carrier frequency offset, so accurate timing synchronization and frequency synchronization are necessary to OFDM system. This p...

This paper deals with Carrier Frequency Offset (CFO) estimation for OFDM systems using repetitive patterns in the training symbol. A theoretical comparison based on Cramer Rao Bounds (CRB) for two kinds of CFO estimation methods has been presented in this paper. Through the comparison, it is shown that the performance of CFO estimation can be improved by exploiting the repetition property and t...