From cde3339a5921aec0d015faea868350d168776a2f Mon Sep 17 00:00:00 2001
From: Eric Kooistra <kooistra@astron.nl>
Date: Mon, 9 Dec 2024 16:26:16 +0100
Subject: [PATCH] Add comment on coefs symmetry.
---
applications/lofar2/model/pfb_bunton_annotated/Gen_filter12.m | 2 ++
1 file changed, 2 insertions(+)
diff --git a/applications/lofar2/model/pfb_bunton_annotated/Gen_filter12.m b/applications/lofar2/model/pfb_bunton_annotated/Gen_filter12.m
index af341478b9..50b22e3bd5 100644
--- a/applications/lofar2/model/pfb_bunton_annotated/Gen_filter12.m
+++ b/applications/lofar2/model/pfb_bunton_annotated/Gen_filter12.m
@@ -77,6 +77,8 @@ title ('Sum of correlator responses for Bin 0 and 1')
% 2304, using Q = 12. The number of FFT blocks remains Ntaps = 12, because
% the shape of cl is the same as for c. The FFT block size now becomes Nfft =
% Kfft * Q = 16 * 12 = 192.
+% Using Q > 1 does cause the FIR filter to become slightly asymmetrical, so
+% the group delay is not exactly constant (Ncoefs - 1) / 2.
Q = 12;
% Y = interpft(X, N) returns a vector Y of length N obtained by interpolation
% in the Fourier transform of X.
--
GitLab