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A Method for Generating Binary Frequency Shift Keyed Signal

IP.com Disclosure Number: IPCOM000037432D
Original Publication Date: 1989-Jan-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Hong, JH: AUTHOR

Abstract

This article describes a method for generating a binary frequency shift keyed signal without using a voltage controlled oscillator.

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A Method for Generating Binary Frequency Shift Keyed Signal

This article describes a method for generating a binary frequency shift keyed signal without using a voltage controlled oscillator.

Referring to the figure, the precoder generates two digital signals a(t) and b(t). These signals are filtered by two identical lowpass filters (LPF) whose pulse response is a half cycle of a sinusoidal signal with the period equal to twice the bit time. The waveforms a(t) and b(t) and their lowpass filtered versions for an arbitrary input data sequence ...0,0,1,1,1,... are shown in the figure.

The two quadrature carrier signals are modulated by the outputs from the lowpass filters and the resulting signals are summed to generate the binary frequency shift keyed signal. The frequency of the output signal is increased or decreased by an amount equal to 1/(2 bit time) when the data is 1 or 0, respectively.

Disclosed anonymously.

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