# What is lag in cross-correlation?

Table of Contents

## What is lag in cross-correlation?

The lag refers to how far the series are offset, and its sign determines which series is shifted. Note that as the lag increases, the number of possible matches decreases because the series “hang out” at the ends and do not overlap.

## How do you find the delay between two signals in Matlab?

Description. d = finddelay( x , y ) returns an estimate of the delay d between input signals x and y . Delays in x and y can be introduced by prepending zeros. d = finddelay( x , y , maxlag ) uses maxlag to find the estimated delay(s) between x and y .

**How do you delay a signal in Matlab?**

Delay Signal by Fractional Number of Samples Assume a sampling rate of 10 kHz. fs = 1e4; t = 0:1/fs:0.005; signal = cos(2*pi*1000*t)’; Set the delay to 0.25 ms or 2.5 samples. delayed_signal = delayseq(signal,0.25e-3,fs);

**How do you find cross-correlation between two signals?**

To detect a level of correlation between two signals we use cross-correlation. It is calculated simply by multiplying and summing two-time series together. In the following example, graphs A and B are cross-correlated but graph C is not correlated to either.

### How do you normalize cross-correlation?

for two variables, the best measure is the correlation coefficient. the cross correlation normalized by the multiplication of the standard deviations. >the sum is taken from 1 till N. >var(x) is the variance of x.

### How is signal delay calculated?

It can be computed as the ratio between the link length and the propagation speed over the specific medium. Propagation delay is equal to d / s where d is the distance and s is the wave propagation speed. In wireless communication, s=c, i.e. the speed of light.

**What is delay block in Simulink?**

The Transport Delay block delays the input by a specified amount of time. You can use this block to simulate a time delay. The input to this block should be a continuous signal. At the start of simulation, the block outputs the Initial output parameter until the simulation time exceeds the Time delay parameter.

**What is delay time?**

Delay time means the difference in time between the change of the component to be measured at the reference point and a system response of 10 per cent of the final reading (t10) with the sampling probe being defined as the reference point.

## What will affect lag time?

Slope – steep slopes lead to rapid water transfer and shorter lag times. Gentle slopes slow down water transfer making the lag time longer. Drainage basin shape – a high density basin has more streams and rivers which speed up water transfer and shorten lag time.

## Can cross-correlation be greater than 1?

The possible range for the correlation coefficient of the time series data is from -1.0 to +1.0. The closer the cross-correlation value is to 1, the more closely the sets are identical.

**How do you calculate total delay?**

Mathematically, Transmission delay ∝ Length / Size of data packet. Transmission delay ∝ 1 / Bandwidth.

**What are the 4 sources of delay?**

The delay of a packet is calculated by adding the following four components: propagation delay, transmission delay, queuing delay, and processing delay.

### What is unit delay in Simulink?

The Unit Delay block holds and delays its input by the sample period you specify. When placed in an iterator subsystem, it holds and delays its input by one iteration. This block is equivalent to the z-1 discrete-time operator. The block accepts one input and generates one output. Each signal can be scalar or vector.

### What is block delay?

The Delay block outputs the input of the block after a delay. The block determines the delay time based on the value of the Delay length parameter. The block supports: Variable delay length. Specification of the initial condition from an input port.

**How to detect the lag in a sample cross-correlation sequence?**

One sequence is a delayed version of the other. The delay is 3 samples. Add N ( 0, 0. 3 2) white noise to the delayed signal. Use the sample cross-correlation sequence to detect the lag. Create and plot the signals. Set the random number generator to the default settings for reproducible results.

**How to detect the lag in a delayed signal?**

One sequence is a delayed version of the other. The delay is 3 samples. Add N ( 0, 0. 3 2) white noise to the delayed signal. Use the sample cross-correlation sequence to detect the lag. Create and plot the signals.

## How to compute cross-correlation between two inputs?

In the time domain, the block convolves the first input signal, u, with the time-reversed complex conjugate of the second input signal, v. In the frequency domain, to compute the cross-correlation, the block: Takes the Fourier transform of both input signals, U and V. Multiplies U and V*, where * denotes the complex conjugate.

## How do you find the cross correlation between two signals?

To compute the cross-correlation, the algorithm: Takes the Fourier transform of both input signals, U and V. Multiplies U and V *, where * denotes the complex conjugate. Computes the inverse Fourier transform of the product.