# What is the time reversal convolution

Given a signal $$r(t)$$ which is a result of convolution between signal $$x(t)$$ and a channel $$h(t)$$ as below :

$$r(t) = h(t)*x(t);$$

what I know, the time reversal convolution can be process as follows : $$y(t) = r(t)*h^*(-t) = h(t)*x(t)*h^H(-t);$$ where * denote to the convolution and $$h^H$$ is the conjugate. I think that right and clear, but what does mean $$h(-t)$$. is it all simply equals to $$conv(r(t), -h(t))$$ for example as below :

x = randn(1,5);
h = randn(1,3);
r = conv(h,x);
y = conv(r,-h);


Is y is correct in the above example? however I think it should be continuous where the above example is discrete signal.