gpsbabel -i nmea,date="20061118" -f 1118.txt -o xcsv,style=/applications/gpsbabel-1.3.1/style/mystyle2.style -F 1118

just copy mystyle.style or  mystyle2.style file into your desktop or somewhere, and use  xcsv,style=/path/mystyle.style
and I changed the file name into 1118.txt

nmea,date="20061118" 

this is the 'date option'

 Complete date-free tracks with given date (YYYYMMDD)..

On input, track points with times but no dates will have this date applied.

This is necessary because some NMEA sentences contain times but no dates. If this option is not specified and the date cannot be determined from one or more of the available NMEA sentences, the tracks will be discarded.

this is what it does.

2) another approach because gpsbabel fails on this file

grep GPRMC 1027.txt | sed 's/,/ /g' | awk '{print $2,$4,$6}' > GPS.txt

now the file looks like this
000114.0 3252.08193 11715.13957
000114.0 3252.08193 11715.13957
000115.0 3252.08193 11715.13957
000115.0 3252.08193 11715.13957

This is time in seconds followed by DDMM.MMMMMM.
We can convert this to decimal degrees in Matlab

%
%   load the data file
%
FORMAT LONG
load GPS.txt
t=GPS(:,1);
ll=GPS(:,2);
ln=GPS(:,3);
%
% get the degrees
%
lld=floor(ll/100.);
ldec=(ll-100*lld)/60;
rll=lld+ldec;
lnd=floor(ln/100.);
ldec=(ln-100*lnd)/60;
rln=lnd+ldec;
%
% make output vector
%
rout=[t-t(1),rll,-rln];