Demodulation method and apparatus incorporating charge coupled devices

Demodulator apparatus for demodulating a data bearing broadcast signal in the absence of mixers and without incurring quantization errors, comprising:

• a) means for receiving a broadcast signal and producing therefrom a predetermined intermediate carrier frequency (F.sub.IF),
• b) charge coupled device connected to receive said intermediate carrier frequency F.sub.IF and having N active stages and tap weight means at each of said stages for entering a tap weight sequence to yield maximum correlation energy when desired alignment occurs to thereby mark phase and frequency agreement between local timing and the received signal, and the frequency F.sub.IF is:
• (N.sub.stage /4)(D.sub.R /2)(K)(1/.alpha.)
• where:
• N.sub.stage correspond to the number of active stages,
• D.sub.R /.sub.2 and .alpha. defines the relationship between the number of active stages and symbol rate of the received signal,
• K.sub.1 is a scaling factor which specifies the number of carrier cycles per four stage block and it is and odd integer .gtoreq.1,
• .alpha. denotes the portion of a symbol, that said transversal charge coupled device spans,
• c) means for sampling said intermediate frequency at a clock rate (F.sub.s) of:
• ##EQU2## wherein F.sub.IF is said intermediate frequency and K is a scaling factor which is related to the number of carrier cycles per stage.

A method for demodulating a data bearing broadcast signal in the absence of mixers and without incurring quantization errors, comprising:

• a) receiving a broadcast signal and producing therefrom an intermediate carrier frequency (F.sub.IF),
• b) providing a charge coupled device (CCD) having N active stages and tap weight means at each of said stages for entering a tap weight sequence to yield maximum correlation energy when desired alignment occurs to thereby mark phase and frequency agreement between local timing and the received signal, and the frequency of F.sub.IF is:
• (N.sub.stage /4)(D.sub.R /.sub.2)(K)(1/.alpha.)
• where:
• N.sub.stage correspond to the number of active stages,
• D.sub.R /.sub.2 and .alpha. defines the relationship between the number of active stages and symbol rate of the received signal,
• K.sub.1 is a scaling factor which specifies the number of carrier cycles per four stage block and it is and odd integer .gtoreq.1,
• .alpha. denotes the portion of a symbol that said transversal filter spans,
• c) sampling said intermediate frequency at a clock rate (F.sub.s) of:
• ##EQU4## wherein F.sub.IF is said intermediate frequency and K.sub.2 is a scaling factor related to the number of carrier cycles per stage.