Patent ID: 7027847
Filing Date: 2006-04-11
Classification: H03G,H04B

Abstract:
1. A communications system for transmitting and receiving a carrier communication signal carrying a voice signal indicative of voice information and a tone signal indicative of data information, comprising: transmission means for transmitting said carrier communication signal carrying said voice signal and said tone signal; and receiving means for receiving said carrier communication signal carrying said voice signal and said tone signal transmitted by said transmission means, said transmission means including: a voice inputting unit for inputting said voice information therethrough to generate said voice signal indicative of said voice information; a data inputting unit for inputting said data information therethrough; a tone signal generating unit for generating said tone signal indicative of said data information on the basis of said data information inputted by said data inputting unit, said tone signal having a plurality of tones each having a signal level and repeated at predetermined time intervals; a mixing unit for mixing said voice signal generated by said voice inputting unit and said tone signal generated by said tone signal generating unit to generate a communication signal carrying said voice signal and said tone signal; a modulating unit for modulating said communication signal carrying said voice signal and said tone signal generated by said mixing unit with a carrier signal to generate a carrier communication signal carrying said voice signal and said tone signal; a transmission unit for transmitting said carrier communication signal carrying said voice signal indicative of said voice information and said tone signal indicative of said data information modulated by said modulating unit, therethrough, and said receiving means including: a receiving unit for receiving said carrier communication signal carrying said voice signal indicative of said voice information and said tone signal indicative of said data information transmitted by said transmission means; a demodulating unit for demodulating said carrier communication signal carrying said voice information and said tone signal received by said receiving unit to generate said communication signal; a voice signal filtering unit for filtering said voice signal indicative of said voice information therethrough from said communication signal generated by said demodulating unit; a tone signal filtering unit for filtering said tone signal therethrough from said communication signal generated by said demodulating unit; an integral computing unit for sequentially computing integrals of said signal levels of said tones of said tone signal passed through by said tone signal filtering unit, at first predetermined time intervals; a data information computing unit for sequentially computing differences between two respective integrals of said signal levels of said tones of said tone signal computed by said integral computing unit, at respective second predetermined time intervals each starting at a leading point and ending at a trailing point to acquire said data information on the basis of said differences; a data information outputting unit for outputting said data information acquired by said data information computing unit, therethrough; and a voice information outputting unit for outputting said voice information on the basis of said voice signal filtered through by said voice signal filtering unit, therethrough, in accordance with said data information outputted by said data information outputting unit.