Synchronization algorithms based on weighted CAZAC preambles for OFDM systems

Abstract

In this paper, we study the performances of preambles with a weighted structure for estimate the Timing Offset and Frequency Offset in Orthogonal Frequency Division Multiplexing (OFDM) systems. We have reviewed the configuration in short and long preambles of weighted preambles, based on Constant Amplitude Zero Auto Correlation (CAZAC) sequences weighted by a Pseudo Noise (PN) sequences. In this paper we have designed short and long preambles with a CAZAC sequence weighted by a Golay Rudin Shapiro sequence and their respective timing metrics. By simulation in MATLAB, we get the Mean Square Error (MSE) of the estimation, the Bit Error Rate (BER) of transmitted data over Rayleigh fading channel with Additive White Gaussian Noise (AWGN), coarse timing and frequency offset.

Performance Analysis of CP-Based and CAZAC Training Sequence-Based Synchronization in OFDM System

“…Figure 2 shows the CP insertion in OFDM packet. Assume S is the CP of the OFDM system, according to [5], it can be represented as in (7). (7) Where j is imaginary number and M is relative prime of N. N itself is a number of subcarrier.…”

“…Meng used the asymmetric model of training sequence which inrcease the robustness in Reyleigh Fading Channel. Silva [5], Silva had reviewed the configuration in short and long preambles of weighted preambles, based on CAZAC sequences weighted by a Pseudo Noise (PN) sequences. He designed short and long preambles with a CAZAC sequence weighted by a Golay Rudin Shapiro sequence and respective timing metrics.…”

Joint timing and frequency synchronization based on weighted CAZAC sequences for reduced-guard-interval CO-OFDM systems

“…In this paper, we propose and demonstrate, for the first time to our knowledge, a joint timing and frequency synchronization algorithm for RGI-CO-OFDM systems using only one training symbol based on a constant amplitude zero autocorrelation (CAZAC) sequence weighted by a pseudo-random noise (PN) sequence. CAZAC sequences, which are a type of polyphase codes, have constant amplitude elements and good periodic autocorrelation properties [18][19][20] and have been applied in wireless communications systems for various applications, including channel estimation [21] and synchronization [22][23][24]. The performance of the proposed technique is demonstrated by means of numerical simulations in a 115.8-Gb/s 16-QAM RGI-CO-OFDM system.…”