% -*- texinfo -*-
% @deftypefn {Function File} {} modmap (@var{method},@var{...})
% @deftypefnx {Function File} {y = } modmap (@var{x},@var{fd},@var{fs},'ask',@var{m})
% @deftypefnx {Function File} {y = } modmap (@var{x},@var{fd},@var{fs},'fsk',@var{m},@var{tone})
% @deftypefnx {Function File} {y = } modmap (@var{x},@var{fd},@var{fs},'msk')
% @deftypefnx {Function File} {y = } modmap (@var{x},@var{fd},@var{fs},'psk',@var{m})
% @deftypefnx {Function File} {y = } modmap (@var{x},@var{fd},@var{fs},'qask',@var{m})
% @deftypefnx {Function File} {y = } modmap (@var{x},@var{fd},@var{fs},'qask/cir',@var{nsig},@var{amp},@var{phs})
% @deftypefnx {Function File} {y = } modmap (@var{x},@var{fd},@var{fs},'qask/arb',@var{inphase},@var{quadr})
% @deftypefnx {Function File} {y = } modmap (@var{x},@var{fd},@var{fs},'qask/arb',@var{map})
%
% Mapping of a digital signal to an analog signal. With no output arguments
% @dfn{modmap} plots the constellation of the mapping. In this case the
% first argument must be the string @var{method} defining one of 'ask',
% 'fsk', 'msk', 'qask', 'qask/cir' or 'qask/arb'. The arguments following
% the string @var{method} are generally the same as those after the
% corresponding string in the fucntion call without output arguments.
% The exception is @code{modmap('msk',@var{Fd})}.
%
% With an output argument, @var{y} is the complex mapped analog signal. In
% this case the arguments @var{x}, @var{fd} and @var{fs} are required. The
% variable @var{x} is the digital signal to be mapped, @var{fd} is the
% sampling rate of the of digital signal and the @var{fs} is the sampling
% rate of the analog signal. It is required that @code{@var{fs}/@var{fd}}
% is an integer.
%
% The available mapping of the digital signal are
%
% @table @asis
% @item 'ask'
% Amplitude shift keying
% @item 'fsk'
% Frequency shift keying
% @item 'msk'
% Minimum shift keying
% @item 'psk'
% Phase shift keying
% @item 'qask'
% @itemx 'qsk'
% @itemx 'qam'
% Quadraure amplitude shift keying
% @end table
%
% In addition the 'qask', 'qsk' and 'qam' method can be modified with the
% flags '/cir' or '/arb'. That is 'qask/cir' and 'qask/arb', etc are valid
% methods and give circular- and arbitrary-qask mappings respectively.
%
% The additional argument @var{m} is the order of the modulation to use.
% @var{m} must be larger than the largest element of @var{x}. The variable
% @var{tone} is the FSK tone to use in the modulation.
%
% For 'qask/cir', the additional arguments are the same as for
% @dfn{apkconst}, and you are referred to @dfn{apkconst} for the definitions
% of the additional variables.
%
% For 'qask/arb', the additional arguments @var{inphase} and @var{quadr} give
% the in-phase and quadrature components of the mapping, in a similar mapping
% to the outputs of @dfn{qaskenco} with one argument. Similar @var{map}
% represents the in-phase and quadrature components of the mapping as
% the real and imaginary parts of the variable @var{map}.
% @end deftypefn
% @seealso{demodmap,dmodce,amodce,apkconst,qaskenco}