MATLAB Answers

# this is the code that i want to run, but got problem Undefined function or variable 'QFix'

조회 수: 4(최근 30일)
muhammad nur adri nawi 2020년 11월 25일
답변: Jon 2020년 11월 25일
close all; clc;
% Example Parameters
B = 6; %# of fractional bits
N = 100000; % # of samples
xn = (2*rand(1,N)-1); % Input sequence - Uniform Distribution
a = 0.9; % Filter parameter
Xm = 1-abs(a); % Scaling factor
% Local variables
bM = 7; DbM = 2^bM; % bin parameter
BB = 2^B; % useful factor in quantization
M = round(DbM/2); % Half number of bins
bins = [-M+0.5:1:M-0.5]; % Bin values from -M to M
Q = bins/DbM; % Normalized bins
YTN = 2^(-bM); % Ytick marks interval
YLM = 4*YTN; % Yaxis limit
% Quantize the input and the filter coefficients
xn = QFix(Xm*xn,B,'round','satur'); % Scaled Input quant to B bits
a = QFix(a,B,'round','satur'); % a quantized to B bits
% Filter output without multiplication quantization
yn = filter(1,[1,-a],xn); % output using filter routine
% Filter output with multiplication quantization
yq = zeros(1,N); % Initialize quantized output array
yq(1) = xn(1); % Calculation of the first sample yq(1)
for I = 2:N;
A1Y = QFix(a*yq(I-1),B,'round','satur'); % Quantization of a*y(n-1)
yq(I) = QFix(A1Y+xn(I),B,'round','satur'); % I-th sample yq(I)
end
% Output Error Analysis
en = yn-yq; % Output error sequence
varyn = var(yn); varen = var(en); % Signal and noise power
eemax = max(en); eemin = min(en); % Maximum and minimum of the error
enmax = max(abs([eemax,eemin])); % Absolute maximum range of the error
enavg = mean(en); enstd = std(en); % Mean and std dev of the error
en = round(en*(2^bM)/(2*enmax)+0.5); % Normalized en (integer between -M & M)
en = sort([en,-M:1:(M+1)]); %
H = diff(find(diff(en)))-1; % Error histogram
H = H/N; % Normalized histogram
Hmax = max(H); Hmin = min(H); % Max and Min of the normalized histogram
% Output SNRs
SNR_C = 10*log10(varyn/varen); % Computed SNR
SNR_T = 6.02 + 6.02*B + 20*log10(Xm); % Theoretical SNR

댓글을 달려면 로그인하십시오.

### 채택된 답변

Jon 2020년 11월 25일
You need to make sure that the directory where the file QFix.m is located is put onto the MATLAB path.
Click the Set Path icon on the HOME tab >ENVIRONMENT on the MATLAB toolbar to add the appropriate directory(s) containing your source code.

댓글을 달려면 로그인하십시오.

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!