You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: gps_channel.m
    path of file: ./repos/gps-stack-sim/lib/txlib
    
    the code of the file until where you have to start completion: function [delay_CA, cicles, prop_delay, sat_clock_offset, sat_clock_rel, iono_T, trop_T_equiv] = gps_channel(head, eph, time, Rpos, sCA, L)

% includes tropo, iono, clock error and relativistic clock
% although the clock errors are not strictly caused by the channel


    
function [delay_CA, cicles, prop_delay, sat_clock_offset, sat_clock_rel, iono_T, trop_T_equiv] = gps_channel(head, eph, time, Rpos, sCA, L)

% includes tropo, iono, clock error and relativistic clock
% although the clock errors are not strictly caused by the channel

[sat_clock_offset, sat_clock_rel, iono_T, trop_T_equiv] = gen_error( head, eph, time, Rpos );
[ prop_delay ] = propagation_delay( head, eph, time, Rpos );

external_delay = sat_clock_offset + sat_clock_rel + iono_T + trop_T_equiv;


[delay_CA, cicles] = apply_delay(sCA, prop_delay, external_delay, L);

end