Need help to fix this Dent Model..

matlab+fm(velocity, carrierfreq)

Im a a new user of MATLAB and used this Dent Model as my reference. I try a lot of code and command to fix the error and missing code but it seems getting worst. If there is anyone who are really helping and advance in MATLAB and willing to help me. I wish you guys always happy and god bless you.

p/s the smiley symbols in the command is not smiling, actually it is combination of : and ). That's why the come out is smiling. really sorry about it.


% Rayleigh Fading Channel Signal Generator Using the Dent Model
%
% Usage:
% [omega_mTau, Tk] =
% ai_RayCh(NumAngles, Length, SymbolRate, NumWaveforms, CarrierFreq,
% Velocity)
%
% Where the output omega_mTau is a time scaling factor for plotting
% normalized correlations. The LAGS value output by [C,LAGS] = XCORR(...)
% should be multiplied by the omega_mTau scaling factor to properly display
% axis. Tk is a two dimensional vector [M, N] = SIZE(Tk) with
% M=numWaverorms and N=Length specified in the RayCh(...) function call
%
% And the input variables are:
%
% NumAngles - scalar power of 2, NumAngles > 2^7 is used to specify the
% number of equally strong rays arriving at the receiver. It used to
% compute the number of oscillators in the Dent model with N0 = numAngles/4
%
% Length - scalar preferably power of 2 for faster computation, Length > 2^17
% is used to specify the length of the generated sequence. Lengths near 1E6
% are close to realistic signals
%
% SymbolRate - scalar power of 2 and is in kilo-symbols-per-sec is used to
% specify what should be the transmission data rate. Slower rates will
% provide slowly fading channels. Normal voice and soem data rates are
% 64-256 ksps
%
% NumWaveforms - scalar used to specify how many 'k' waveforms to generate
% in the model. NumWaveforms > 2 to properly display plots
%
% CarrierFreq - scalar expressed in MHz is the carrier frequency of the
% tranmitter. Normally 800 or 1900 MHz for mobile comms
%
% Velocity - scalar expressed in km/hr is the speed of the receiver.
% 100 km/hr = 65 mi/hr. Normal values are 20-130 km/hr
%
% Usage Examples:
% [omega_mTau, Tk] = ai_RayCh(2^7, 2^18, 64, 2, 900, 100)
%
% where
%
% NumAngles=2^7, Length=2^18, symbolRate=64, NumWaveforms=2, carrierFreq=900, Velocity=100
% [omega_mTau, Tk] = RayCh(NumAngles, Length, symbolRate, NumWaveforms,
% carrierFreq, Velocity);
%
% fm - doppler frequency ( the maximum Doppler shift arising from the motion of the mobile.


function [omega_mTau, Tk] = ai_RayCh(NumAngles, Length, symbolRate, NumWaveforms, carrierFreq, Velocity)

% Number of oscillators
N0 = NumAngles/4;

% Maximum Doppler shift of carrier at some wavelength
omega_m = (2*pi)*fm(Velocity, carrierFreq);
% specify variance of the Rayleigh channel
% use this for *constant* variange - requires changing other params in prog
sigma2 = 10;
% make sigma2 a gaussian RV around u = sigma2 and var = sigma2/5
% use for *non constant* variaance - requires changing other params in prog
sigma2 = sigma2 + sqrt(sigma2/5) .* randn(1,NumWaveforms);
% Initialize phases
alpha_n = []; beta_n = []; theta_nk = [];
% make a hadamard matrix
Ak = hadamard(N0);
% determine phase values 'alpha' and 'beta'
n=[1:N0];
alpha_n = 2*pi*n/NumAngles - pi/NumAngles;
beta_n = pi*n/N0;

% convert to time scale using 'fs' sampling frequency
t=[1/(symbolRate*1000):1/(symbolRate*1000):1/(symbolRate*1000) * Length];

Tk = [];
for q = 1 : NumWaveforms

rand('state',sum(100*clock)) % reset randomizer
theta_nk = rand(1,length) * 2 *pi; % create uniform random phase in range [0,2pi]

sumRes = 0;
for i = 1 : N0
term1 = Ak(NumWaveforms,i);
term2 = cos(beta_n(i)) + j*sin(beta_n(i));
term3 = cos(omega_m .* t .* cos(alpha_n(i)) + theta_nk(i));
sumRes = sumRes + (term1 .* term2 .* term3);
end

Tk(q, = sqrt(2/N0) .* sumRes;
% use line below to apply *non-constant* variance
Tk(q, = repmat(10.^(sigma2(q)/20),1, Length) .* Tk(q,; %apply variable in dB

end

% apply *constant* variance unilaterly in dB
% Tk = repmat(10^(sigma2/20), k, Length) .* Tk;


% plot results
figure(20); subplot(3,1,1); semilogy(t,abs(Tk(1,));
xlabel('Time (sec)'); ylabel('Signal Strength (dB)');
title(['Received Envelope, Symbol Rate = ', num2str(symbolRate), ',Carrier = ', num2str(carrierFreq), ', Velocity = ', num2str(Velocity)]);
% compute auto and cross correlations and plot them
omega_mTau = (1/(symbolRate*1000)) * (omega_m/(2*pi)); % compute omega_m * tau scaling
[C1, Lags] = crosscorr(Tk(1,, Tk(2,, 20000);
[C2, Lags2] = autocorr(Tk(1,, 20000);
figure(20); subplot(3,1,3); plot(Lags * omega_mTau, C1);
xlabel('Normalized Time Delay'); ylabel('Normalized Crosscorrelation');
title('Crosscorrelation between waveforms k=1 and k=2');
figure(20); subplot(3,1,2); plot(Lags2 * omega_mTau, C2);
xlabel('Normalized Time Delay'); ylabel('Normalized Autocorrelation');
title('Autocorrelation of the first waveform k=1');

matlab xcorr crosscorr

please help me to fix this type of model..if i know how to fix it, i will do it myself, but for now im quite a beginner in matlab and really need help. please..