Applications of the digital correlator (original) (raw)

AN EDUCATIONAL COMPUTER TOOL TO ANALYZE THE CORRELATOR

Today, the knowledge about techniques of digital signals transmission is fundamental for telecommunications engineering students. As another time the COMPACT DISC substituted the vinyl, nowadays the analog transmission links are being replaced by digital ones. In digital communication systems, there are some devices that are used to optimize the signal to noise ratio in the receiver. This procedure improves the performance of the system, reducing the bit error rate. The most common technique used to receive digital signal is the correlator, which is an optimum method to detect digital signals in Additive White Gaussian Noise channels. The purpose of this paper is to show a didactical approach to analyze the correlator, using a computer program to presents each step in the detection of a digital signal.

A 4 Bit Quantized Skip Algorithm Software Correlator for Microcomputer Systems

This paper gives the design features / paremeters of a prototype software correlator suitable for flowmeters based on the cross-correlation principle. The algorithm used is a "skip" one (Lumley, 1978); it minimizes the processing load while it achieves adequate repeatability in correlogram representation and therefore increases the BW of the processed signals.

Correlation: a brief introduction

International Journal of Electrical Engineering Education, 2014

An important concept in many applications is the correlation function between two signals. The correlation function is more of a measure of similarity between functions. In spite of the importance of the correlation function, it is not covered in most books on signals and systems and signal processing. The few books that cover it do not provide examples students can follow. This paper provides a simple introduction to the correlation function in continuous-time and discrete-time. It provides graphical examples and MATLAB examples.

An ultra-high-speed FPGA based digital correlation processor

IEICE Electronics Express, 2015

This paper presents an ultra-high-speed correlation processor for FPGA (Field-Programmable Gate Array) which is based on MDF (multiplepath delay feedback) pipelined FFT (fast Fourier transform) architecture. In order to decrease the resource cost and processing delay, the FFT processor is based on DIF (Decimation in Frequency) decomposition method, and the IFFT processor is based on DIT (Decimation in Time) decomposition method. The data input and output of the correlation processor are both in natural order. The main clock speed of the processor FPGA implementation can be higher than 200 MHz and is able to process continuous complex input at more than 1.6 Gsps (giga samples per second).

A correlation for the detection of time and frequency offsets

2009

A correlation is proposed for use to detect time and frequency offsets in a received signal in a digital transmission system. Applications include time and frequency synchronization in a single frequency network; pre-distortion for high power amplifiers in a transmitter. The correlation is formed with the products of two pairs of transmitted samples and received samples. The same correlation can be used to detect both time and frequency offsets in the received signal.

Experimental Systems Implementation of a Hybrid Optical–Digital Correlator

Applied Optics, 1999

A high-speed hybrid optical-digital correlator system was designed, constructed, modeled, and demonstrated experimentally. This correlator is capable of operation at approximately 3000 correlations͞s. The input scene is digitized at a resolution of 512 ϫ 512 pixels and the phase information of the two-dimensional fast Fourier transform calculated and displayed in the correlator filter plane at normal video frame rates. High-fidelity reference template images are stored in a phase-conjugating optical memory placed at the nominal input plane of the correlator and reconstructed with a high-speed acousto-optic scanner; this allows for cross correlation of the entire reference data set with the input scene within one frame period. A high-speed CCD camera is used to capture the correlation-plane image, and rapid correlation-plane processing is achieved with a parallel processing architecture. A.-R. Pourzand, and M. Duelli were with the Institute of Microtechnology, University of Neuchâtel, Rue A-L Breguet 2, CH-2000, Neuchâtel, Switzerland. A. Grattarola and C. Braccini were with the

A computationally efficient correlator for pseudo-random correlation systems

2000 IEEE Sixth International Symposium on Spread Spectrum Techniques and Applications. ISSTA 2000. Proceedings (Cat. No.00TH8536), 2000

Pseudo-random correlation systems fmd their application in many engineering fields like, communications, nondestructive testing, medical imaging, and geophysics. The heart of such systems is a correlator, which performs the crosscorrelation between the received signal and a reference waveform. A new method of DSPbased correlator implementation is discussed. It exploits the structural characteristics of pseudo-random waveforms and performs the crosscorrelation of any digitized waveform with a reference pseudo-random waveform, in a manner, much more efiicient in terms of processing speed and hardware requirements. This new method can be applied for baseband or bandpass waveforms, and it can handle a wide range of modulation schemes and signaling structures. In order to achieve greater resolution of the calculated correlation function, it is possible to compute the correlation function for the lag values in fraction of the basic chip interval.

Hardware Implementation of an Efficient Correlator for Interleaved Complementary Sets of Sequences

Journal of Universal Computer Science, 2007

Some sensor systems are characterized by multiple simultaneous aperiodic emissions, with low signal-to-noise ratio and asynchronous detection. In these systems, complementary sets of sequences can be used to encode emissions, due to their suitable auto-correlation and cross-correlation properties. The transmission of a complementary set can be accomplished by interleaving the sequences of the set, generating a macro-sequence which is easily transmitted by a BPSK modulation. The detection of the macrosequence can be performed by means of efficient correlation algorithms with a notably decreased computational load and hardware complexity. This work presents a new hardware design in configurable logic of an efficient correlator for macrosequences generated from complementary sets of sequences. A generic implementation has been achieved, so the configuration can be changed according to the requirements of the application. The developed correlator has been tested in an ultrasonic pulse compression system in which real-time is needed. However, it is applicable in any multi-sensor or communication system where the goal is to make simultaneous emissions from different independent sources, minimizing mutual interference.