1 function [rc, phiests] = phaseNoiseCorr(r, M, phoffset, blocksize)
2 %% Phase noise correction.
4 %% - r: Received symbols
5 %% - M: Order of constellation, M=4 for QPSK
6 %% - phoffset: Phase of the 0th symbol in the constellation
7 %% - blocksize: Viterbi-Viterbi algorithm block size
9 %% - rc: Symbols with corrected phase
10 %% - phiests: Estimates of the phase noise
13 phiests = zeros(1, n);
16 for l = 1 : blocksize : n
17 block = r(l : min(l + blocksize - 1, n));
19 sum_M = sum(block .^ M);
20 phi_est = angle(sum_M .* exp(1j * M * phoffset)) / M;
24 phi_prev = phiests(l - 1);
25 m = floor(0.5 + (phi_prev - phi_est) * M / (2 * pi));
26 phi_est = phi_est + m * 2 * pi / M;
29 block = block .* exp(1j * -phi_est);
30 rc(l : min(l + blocksize - 1, n)) = block;
31 phiests(l : min(l + blocksize - 1, n)) = phi_est;