From 74ea0995719d97ccac33ca908715d16e422197d5 Mon Sep 17 00:00:00 2001
From: Erik Kooistra <kooistra@astron.nl>
Date: Thu, 30 Nov 2017 10:39:03 +0000
Subject: [PATCH] Normalize LOFAR FIR coeff.
---
applications/apertif/matlab/one_pfb.m | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/applications/apertif/matlab/one_pfb.m b/applications/apertif/matlab/one_pfb.m
index 85c8afe488..09573c5ab0 100644
--- a/applications/apertif/matlab/one_pfb.m
+++ b/applications/apertif/matlab/one_pfb.m
@@ -89,7 +89,7 @@ fig=0;
%% Selectable test bench settings
tb.model_filterbank = 'Free choice'; % 'LOFAR' = use fixed settings of LOFAR subband filterbank, else use free choice of tb.nof_subbands and PFIR coefficients
-%tb.model_filterbank = 'LOFAR';
+tb.model_filterbank = 'LOFAR';
if strcmp(tb.model_filterbank, 'LOFAR')
tb.model_quantization = 'fixed point';
tb.nof_subbands = 512;
@@ -100,13 +100,13 @@ else
end
% Input signal 'sinusoid' carrier frequency
-tb.subband_wg = 47; % subband range 0:tb.nof_subbands-1, can be fraction to have any sinusoid frequency
+tb.subband_wg = 47.4; % subband range 0:tb.nof_subbands-1, can be fraction to have any sinusoid frequency
%tb.subband_wg = 1.55;
%tb.subband_wg = 12;
% Model a frequency sweep of the 'sinusoid'
tb.chirp = 0; % 0 = use fixed tb.subband_wg frequency, else increment WG frequency every block to have chirp frequency sweep
-tb.chirp = 1;
+%tb.chirp = 1;
if tb.chirp
tb.nof_tsub = 200; % number of subband periods to simulate
else
@@ -205,6 +205,7 @@ if strcmp(tb.model_filterbank, 'LOFAR')
ctrl_pfir_subband.data_w = 16;
ctrl_pfir_subband.config.design = 'lofar file';
hfir_subband_coeff = load('data/Coeffs16384Kaiser-quant.dat');
+ hfir_subband_coeff = hfir_subband_coeff/max(hfir_subband_coeff);
else
% Calculate free choice PFIR coefficients (can be floating point or fixed point)
ctrl_pfir_subband.nof_taps = 16; % Number of taps
@@ -415,7 +416,7 @@ figure(fig);
data = data_pfir_subband.';
plot(ts, data(:))
title(sprintf('Subband PFIR filter output - FFT input data (WG subband %6.3f)', tb.subband_wg));
-ylim([-2 2]); % Delay tracking step when tb.subband_wg is .5 causes double range
+ylim([-3 3]); % Delay tracking step when tb.subband_wg is .5 causes double range
xlabel(sprintf('Time 0:%d [Tsub]', tb.nof_tsub-1));
ylabel('Voltage');
grid on;
--
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