function sinusoid = gen_ddc_sinusoid(carriers,fs_dds,length,bits)
% GEN_DDC_SINUSOID    Generates a sinusoid vector or sinusoid array of the
% specified frequencies for a down converter.
% Carrier arrays are presented one carrier per column.

%% Create a sinusoid to model against
fdds = carriers./fs_dds;
ph = fdds * ([0:length-1]);
sinusoid = (2^(bits-1)-1)/2^bits * exp(-j.* 2.*pi.*ph);
sinusoid = sinusoid.';