Why does running this function result in " Unexpected MATLAB operator" at the first line of measurment?

function [ber, numBits]=chap4_ex02(EbNo, maxNumErrs, maxNumBits)
%%Constants
FRM=2400; % Size of bit frame
%%Modulation Mode
% ModulationMode=1; % QPSK
% ModulationMode=2; % QAM16
ModulationMode=2; %QAM64
k=2*ModulationMode; % Number of bits per modulation symbol
snr = EbNo + 10*log10(k);
noiseVar = 10.^(0.1.*(-snr)); % Compute noise variance
%%Processing loop: transmitter, channel model and receiver
numErrs = 0;
numBits = 0;
nS=0;
while ((numErrs < maxNumErrs) && (numBits < maxNumBits))
% Transmitter
u = randi([0 1], FRM,1); % Randomly generated input bits
t0 = Scrambler(u, nS); % Scrambler
t1 = Modulator(t0, ModulationMode); % Modulator
% Channel
c0 = AWGNChannel(t1, snr); % AWGN channel
% Receiver
r0 = DemodulatorSoft(c0, ModulationMode, noiseVar); % Demodulator
r1 = DescramblerSoft(r0, nS); % Descrambler
y = 0.5*(1-sign(r1)); % Recover output bits
% Measurements
numErrs = numErrs + sum(ỹ=u); % Update number of bit errors
numBits = numBits + FRM; % Update number of bits processed
% Manage slot number with each subframe processed
nS = nS + 2;
nS = mod(nS, 20);
end
%%Clean up & collect results
ber = numErrs/numBits; % Compute Bit Error Rate (BER)

Answer 1

[Sean de Wolski]

First:

numErrs = numErrs + sum(ỹ=u)

One = sign is assignment, so you are trying to assign u to y which is illegal. You probably mean y==u. Second, for some reason there is a ~ above the characters. This possibly comes from a different keyboard or from copying this from a website. I went ahead and retyped the line and it looks good now:

numErrs = numErrs + sum(y==u)

And, most importantly, the way I found this is because the code analyzer was flagging the line as red on the right hand side of the editor

Answer 2

[Ashik Rai]

Its something like this actually.

numErrs = numErrs + sum(y ~= u);