Unexpected Bit Error Rate results when simulating IEEE 802.11p in Rayleigh and Rician channel using WLAN toolbox and Communications Toolbox

I'm trying to simulate the Bit Error rate of Vehicle to Vehicle communications using the IEEE 802.11p standard at it's different MCS's in an AWGN, Rician and Rayleigh channel as well as according to the nodes mobility. When running a monte carlo simulation with just the AWGN channel, the results appear as expected. However, when adding in a Rician or a Rayleigh channel, the results seem incorrect as shown below:

What i expect the results to look like is show below:

The code i used is shown below. The first code block is the one that does the monte carlo simulation and the second code block is the one that creates the channels as well as the WLAN signal and transmits it through each channel. I've tried various different configuration for the channel setup, however the results remain consistently unexpected.

clear all;
clc

rng(0, "combRecursive");

%% Define SNR range (dB) and total errors
snrRange = 0:2:30;

%% Preallocate arrays to store BER values for each SNR
berVehicle = zeros(8,length(snrRange));

%% Set the parameters
speedVehicle1 = 0; % in km/h
vehicleSpeed1 = speedVehicle1 / 3.6; % Speed of Vehicle 1 in m/s

carrierFrequency = 5.9e9; % WLAN carrier frequency in Hz

dopplerShift1 = (vehicleSpeed1 * carrierFrequency) / physconst('LightSpeed');
dopplerShift2 = (vehicleSpeed2 * carrierFrequency) / physconst('LightSpeed');

%% Monte Carlo Simulation
n=8;
parfor i = 1:length(snrRange)
    for mcs = 1:n
        berVehicle3(mcs,i) = BER_vs_SNR_draft_2(snrRange(i), dopplerShift1, mcs-1);
        fprintf("SNR: %d\n", snrRange(i));

    end
end

%% Plot BER vs SNR
figure;
markers = ["-o", "-+", "-*", "-x","-square","-^","-diamond","-pentagram"];
for i = 1:8
    semilogy(snrRange, berVehicle3(i,:), markers(i));
    hold on;
end
xlabel('SNR (dB)');
ylabel('Bit Error Rate (BER)');
title('Bit Error Rate vs. SNR at ', speedVehicle1);
grid on;
legend("BPSK 1/2", "BPSK 3/4", "QPSK 1/2", "QPSK 3/4", "16 QAM 1/2", "16 QAM 3/4", "64 QAM 2/3", "64 QAM 3/4");
hold off;

function [BER] = BER_vs_SNR_draft_2(snrRange, dopplerShift1, mcs)

%% Create channel objects for each vehicle
%ricianchan = comm.RicianChannel(NormalizePathGains=true);
ricianchan = comm.RicianChannel();
ricianchan.SampleRate = 9000;
% ricianchan.PathDelays = [0 1.5e-6];
% ricianchan.AveragePathGains = [0 -3];
ricianchan.KFactor = 6;
% ricianchan.MaximumDopplerShift = dopplerShift1;
% ricianchan.DirectPathDopplerShift = dopplerShift1;


rayleighchan = comm.RayleighChannel();
rayleighchan.SampleRate = 12e9;
%rayleighchan.PathDelays = (0:5:15)*1e-6;
% rayleighchan.AveragePathGains = [0 -3 -6 -9];
% rayleighchan.KFactor = 4;
rayleighchan.MaximumDopplerShift = dopplerShift1;

% AWGN channel
awgnchan = comm.AWGNChannel("NoiseMethod", "Signal to noise ratio (SNR)");

%% Generate and transmit waveform from Vehicle

Errors = 0;
Loops = 0;
cfgNonHT1 = wlanNonHTConfig('ChannelBandwidth','CBW10', 'MCS', mcs, 'PSDULength', 512); % 400 bytes from a research paper
snr = snrRange;
awgnchan.SNR = snr;

field = 'NonHT-Data';
noiseVarEst = 10^(-snr/10);
dataVehicle1 = randi([0 1], 8*cfgNonHT1.PSDULength, 1);  % multiplying by 8 to convert to bits

    while Loops <= 2000
        
        % Form and transmit packet
        txWaveform1 = wlanWaveformGenerator(dataVehicle1, cfgNonHT1);

        % Received signal
        
        rxWaveform1 = awgnchan(txWaveform1);
        rxWaveform1 = ricianchan(rxWaveform1);

        % Recover data
        ind = wlanFieldIndices(cfgNonHT1,field);
        rx1 = rxWaveform1(ind(1):ind(2),:);

        sym1 = wlanNonHTOFDMDemodulate(rx1,field,cfgNonHT1);

        info = wlanNonHTOFDMInfo(field,cfgNonHT1);
        sym1 = sym1(info.DataIndices,:,:);
        
        rxDataBits1 = wlanNonHTDataBitRecover(sym1, noiseVarEst, cfgNonHT1);

        % Calculate BER for vehicle
        Errors = Errors + sum(dataVehicle1 ~= rxDataBits1);
        

        fprintf("SNR: %d, Errors: %d, Loop: %d, MCS: %d\n", snr, Errors, Loops, mcs);
        Loops = Loops + 1;
    end
    fprintf("Final Errors: %d, ", Errors);
    Total_bits_tx = Loops * 8*cfgNonHT1.PSDULength;

    BER = Errors / Total_bits_tx;

[Pooja Kumari]

Can you tell what is the vehicleSpeed2 in the first block of code?

[Matthew Main]

So I don’t actually have a vehicleSpeed2, it was just there for testing purposes. The dopplerShift2 line can be ignored.