%function [cnt_meas,st_channelGrid,st_initConfig,st_mobileStations,st_baseStation,st_measurement] = ofdma_sfn_Cellular_la_dl_simulator(st_channelGrid, st_initConfig,st_baseStation,st_measurement,st_mobileStations)
function st_initConfig = ofdma_sfn_Cellular_la_dl_simulator(st_channelGrid, st_initConfig,st_baseStation,st_measurement,st_mobileStations)
%__________________________________________________________________________
% Type:                 :   File Header
% File name             :   ofdma_sfn_Cellular_la_dl_simulator
% File Description      :   contains the function to simulate OFDMA signle
%                           frequency cellular link adapted downlink
%                           simulator
%__________________________________________________________________________
%
%__________________________________________________________________________
% Type:                 :   Function Header
% Function name         :   ofdma_sfn_Cellular_la_dl_simulator
% input                 :   st_channelGrid,st_initConfig,st_mobileStations,st_baseStations
% output                :   st_channelGrid,st_initConfig,st_mobileStations,st_baseStations
%                       :
% calling functions     :   input_config
% called functions      :
% Function Description  :   Algorithm to be put in here: As of now refer to
%                           design document:simulate OFDMA signle
%                           frequency cellular link adapted downlink
%                           simulator
%__________________________________________________________________________

cnt_meas=0; % counter for measurement module
% For as many frames as required
% figure(1);plothex(st_initConfig.locBS,st_initConfig.fib);
% title('Cell Layout')

MobileIdCnt =0;%counter for mobile identifier number
warning('off','all')

% pre-allocate the user-info to be saved.
user_velocity = uint8(zeros(st_initConfig.nuMob,st_initConfig.saveUserInfo_factor));
user_distance = uint16(zeros(st_initConfig.nuMob,st_initConfig.saveUserInfo_factor));
user_ActiveCnt = uint16(zeros(st_initConfig.nuMob,st_initConfig.saveUserInfo_factor));
user_sinr = int8(zeros(st_initConfig.nuMob,st_initConfig.saveUserInfo_factor,st_baseStation.nuSubChannels));
user_sinr_noFeedBackErr = int8(zeros(st_initConfig.nuMob,st_initConfig.saveUserInfo_factor,st_baseStation.nuSubChannels));
user_mobID = uint16(zeros(st_initConfig.nuMob,st_initConfig.saveUserInfo_factor));
user_fair = (zeros(st_initConfig.nuMob,st_initConfig.saveUserInfo_factor));
for lp_nFrames=1:st_initConfig.nusubFrames % This has to be changed to run for number fo seconds
    % where users die and are born
    % until the simulation time is over

    %INCLUDE ONE MORE LEVEL OF LOGIC, WHERE USERS ARE GENERATED ONLY AT
    %THE 2/5/10/20 MS BOARDER


    % This assumes that for the 2 ms frame , one user gets the same set of
    % sub carriers continuously. i.e. there is no Time Frequency
    % scheduling. Only Frequency domain scheduling.

    % THIS HAS TO CHANGE LATER ON TO PER 0.5 MS, SO THAT TIME FREQUENCY
    % SCHEDULING CAN BE VERIFIED. THIS CAN BE DONE VERY EASILY BY JUST
    % CHANGING THE DEFINITION OF 'st_initConfig.nuOfdmSymbPerFrame' IN THE
    % TEST CONFIG FILE , AS OF NOW THERE IS NO 2 MS, ALL ARE 0.5 MS .

    % WHEN THAT CHANGE WILL BE DONE, THEN THE SCHEDULER HAS TO BE UPDATED
    % SO THAT A MATRIX IS MADE WHICH IS HAVING TIME FREQUENCY DIMENSION,
    % WHERE MOBILE INDEXS WILL BE STORED WHICH WILL IDENTIFY THE TIME
    % FREQUENCY RESOURCE TO BE ALLOCATED TO THE MOBILE. THIS INFORMATION
    % HAS TO BE UPDATED EVERY 2/5/10/20 MS, WHERE AS THIS MATRIX SHOULD BE
    % READ EVERY 0.5 MS FOR SUB CARRIER ALLOCATION



    st_initConfig.nFrmCnt=lp_nFrames;
    st_initConfig.nFrmCntSlot=mod(lp_nFrames-1,st_initConfig.nuFrmPerSlot)+1;
    save_UserInfor_times = ceil(lp_nFrames/st_initConfig.saveUserInfo_factor); % how many times has been saved
    save_UserInforCnt = mod(lp_nFrames-1,st_initConfig.saveUserInfo_factor) + 1;

    % as of now this function will create a random drop of users this will be
    % changed very soon where users who have finished trasmitting will quit the
    % system while new users will join
    switch st_initConfig.measure_g_factorFlg
        case 'yes'
            % do not use the frequency selective fading and do not consider
            % handover
            need correction
            [st_channelGrid,st_initConfig,st_mobileStations,MobileIdCnt,st_baseStation,st_measurement]=update_mobile_structres_before_frame_g_fac_no_fsf(st_initConfig,st_channelGrid,st_mobileStations,MobileIdCnt,st_baseStation,st_measurement);
            switch st_initConfig.handOffFlg
                case 'handoff'
                    need correction
                    [cnt_meas,st_measurement,st_mobileStations] = measurementGfactor(cnt_meas,st_channelGrid,st_measurement,st_baseStation,st_mobileStations,st_initConfig);
                case 'nofsfnohandoff'
                    need correction
                    [cnt_meas,st_measurement,st_mobileStations] = measurementGfactorNoHandOff(cnt_meas,st_channelGrid,st_measurement,st_baseStation,st_mobileStations,st_initConfig);
            end
        case 'no'
            % use frequency selective fading

            % as of now this function will create a random drop of users and update
            % user locations and users who have finished trasmitting will quit the
            % system while new users will join
            [st_channelGrid,st_initConfig,st_mobileStations,MobileIdCnt,st_baseStation,st_measurement]= update_mobile_structres_before_frame2(st_initConfig,st_channelGrid,st_mobileStations,MobileIdCnt,st_baseStation,st_measurement);

            %-----------------------------
            % Get Feedback and adjust for feedback delay
            %-----------------------------
            % There can be several factors for feedback, for example
            % average SINR, in each sub band (for sub carrier allocation)
            % average rms delay spread and average Doppler Condition
            % only average path loss parameter
            % As of now, since the first version will include only random sub
            % carrier allocation, therefore there is no need to feedback detailed
            % CSI.

            % 1. Measure the SINR per sub channel of each mobile
            % 2. Store in each mobile station structure
            [st_mobileStations,st_channelGrid] = measureMobileSinr2(st_initConfig,st_baseStation,st_channelGrid,st_mobileStations);
            %end
            if mod(st_initConfig.nFrmCnt-1,st_initConfig.F_LA)==0
                %-----------------------------
                % CALL LINK ADAPTATION ALGORITHM THEN
                % CALL SCHEDULING ALGORITHM : THESE ARE FOR TESTING LA PERFORMANCE
                %-----------------------------
                % Store the suitable rate, per mobile, per sub carrier, considering
                % 1. power adaptation is not done
                % 2.
                % scheduler will take this information and allocate only a few resource
                % units to one user, though the user measures the performance of all
                % resource units
                [st_baseStation,st_mobileStations,st_measurement] = link_adaptation(st_initConfig,st_baseStation,st_channelGrid,st_mobileStations,st_measurement);
                %-----------------------------
                % allocates resources (time frequency chunks) to users
                % TO call the RA block only once per FRAME, which is the unit
                % for AMC, though power control can be done at a faster rate
                [st_baseStation] = resource_alloc(st_baseStation, st_mobileStations, st_initConfig);
                % OR
                % CALL JOINT LINK ADAPTATION + SCHEDULING ALGORITHM: THIS IS THE NEW
                % ALGORITHMS THAT ARE TO COME OUT
            elseif mod(st_initConfig.nFrmCnt-1,st_initConfig.F_PA)==0
                % power control algorithm function call