i) Consider the following system: y[k]+ay[k-1]+...+any[kn] =bu[k]+bu[k-1]+...+bmu[km] + e[k] What minimum order of persistence of excitation should the input have to identify the parameters of this system? Explain in detail. ii) Consider the problem of identifying the following system: S: Sy[k]=bu[k 1] + bu[k 2] + ... + bu[kn] + e[k] - = Determine for what model order n, do the parameters of the system h,, i 1... n, can be uniquely identified for each of the following input signals. treat the asymptotic case where data is available for k=1... N, N a) u[k] = 1 b) u[k] = (-1)" c) u[n] = 1 + (-1)"