amod.hlp

数字通信第四版原书的例程

amdsb-sc_help_begin
AMOD   Amplitude modulation, double sideband suppressed carrier.
       Y = AMOD(X, Fc, Fs, METHOD), METHOD = 'amdsb-sc', modulates the input
       signal X with carrier frequency Fc (Hz) and sample frequency Fs (Hz)
       using amplitude modulation, double sideband suppressed carrier method.
       When Fs is a two element vector, the second element in the vector is
       the initial phase (rad) of the carrier signal.
amdsb-sc_help_end

amdsb-tc_help_begin
AMOD   Amplitude modulation, double sideband with transmission carrier.
       Y = AMOD(X, Fc, Fs, METHOD, OFFSET), METHOD = 'am' or 'amdsb-tc',
       modulates the message signal X with carrier frequency Fc (Hz) and
       sample frequency Fs (Hz) using double sideband with transmission
       carrier. OFFSET is the value subtracted from X prior to
       modulation. When OFFSET is omitted, the function sets the default
       OFFSET = abs(min(X)). When Fs is a two element vector, the second
       element in the vector is the initial phase (rad) of the carrier
       signal.
amdsb-tc_help_end

amssb_help_begin
AMOD   Amplitude modulation, single side band suppressed carrier.
       Y = AMOD(X, Fc, Fs, METHOD), METHOD = 'amssb', modulates the message
       signal X with carrier frequency Fc (Hz) and sample frequency Fs (Hz)
       using amplitude modulation, single sideband suppressed carrier method.
       A frequency domain Hilbert transform computation method is used. When
       Fs is a two element vector, the second element in the vector is the
       initial phase (rad) of the carrier signal.

       Y = AMOD(X, Fc, Fs, METHOD, Hil_Flt), METHOD = 'amssb'.
       Use time domain Hilbert filter with its numerator and denominator given
       by the default calculation:  [NUM, DEN] = HILBIIR(1/Fs);

       Y = AMOD(X, Fc, Fs, METHOD, Hil_Flt, DEN), METHOD = 'amssb'.
       Use time domain Hilbert filter with its numerator and denominator given
       in NUM=Hil_Flt and DEN. For best results, please use the compensator in
       Hilbert filter design. The Hilbert filter can be designed by
       [NUM, DEN] = HILBIIR(1/Fs); or
       [NUM, DEN] = HILBIIR(1/Fs, DELAY, BANDWIDTH).
amssb_help_end

qam_help_begin
AMOD   Quadrature Amplitude modulation.
       Y = AMOD(X, Fc, Fs, METHOD), METHOD = 'qam', modulates a message signal
       X with carrier frequency Fc (Hz) and sample frequency Fs (Hz) using
       quadrature amplitude modulation METHOD. The input signal X is a even
       column matrix with the odd columns as the in-phase signal and even
       columns as the quadrature signal. When Fs is a two element vector, the
       second element in the vector is the initial phase (rad) of the carrier
       signal.
qam_help_end

fm_help_begin
AMOD   Frequency modulation.
       Y = AMOD(X, Fc, Fs, METHOD), METHOD = 'fm', modulates a message signal
       X with carrier frequency Fc (Hz) and sample frequency Fs (Hz) using
       frequency modulation method. The modulated signal takes the spectrum
       from min(X) + Fc to max(X) + Fc. When Fs is a two element vector, the
       second element in the vector is the initial phase (rad) of the carrier
       signal.

       Y = AMOD(X, Fc, Fs, METHOD, SENSITIVE), METHOD = 'fm', specifies the
       sensitivity in the modulation.
fm_help_end

pm_help_begin
AMOD   Phase modulation.
       Y = AMOD(X, Fc, Fs, METHOD), METHOD = 'pm', modulates a message
       signal X with carrier frequency Fc (Hz) and sample frequency Fs (Hz)
       using phase modulation method. When Fs is a two element vector, the 
       second element in the vector is the initial phase (rad) of the carrier
       signal.

       Y = AMOD(X, Fc, Fs, METHOD, SENSITIVE), METHOD = 'pm', specifies the
       sensitivity in the modulation.
pm_help_end

Wes Wang 9/30/95