digital communnication matlab problem

Hello everyone, im new to matlab and i've come across this problem which i have no clue on what to do, if anyone can help me with it i would appreciate it very much, the problem is stated below. thank you in advance for your cooperation.

The signal x ( t ) = sin (20 p t ) + 0.25sin (10 p t ) is digitized

using DM.

a. The signal is sampled at 1.28 kHz to obtain x[n]. Using

step size step = 1/15, generate the delta-modulation representation

y[n]. Plot it.

xq(1) = 0; y(1) = 1;
for k = 2:N;
w1= x(k) - xq(k-1) ;
y(k) = sign(w1);
xq(k) = xq(k-1) 1 y(k)*step;
end

b. Reconstruct xq[n] by accumulating y[n]. Recover

the signal xhat by passing xq[n] through an LP filter.

Plot x[n] and xhat[n] on the same figure and

comment.

xq(n) 5 xq(n-1) 1 y(n)*step;
xhat 5 filter(b,a,xq);

c. Repeat (a) and (b) for step size Δ 5 1/20. Comment on

your results

d. Calculate the mean-square error between the original and

quantized sample values. Compare it with one obtained

using uniform quantization.

[KALYAN ACHARJYA]

Is there any specific issue?