Use of feature characteristics including times of occurrence to represent independent bit streams or groups of bits in data transmission systems

• US 6,233,254 B1
• Filed: 03/20/1998
• Issued: 05/15/2001
• Est. Priority Date: 06/06/1997
• Status: Expired due to Fees

• Current Assignee: Glen A. Myers
• Original Assignee: Glen A. Myers
• Inventors: Myers, Glen A.
• Primary Examiner(s): Ton, Dang
• Application Number:
  US09/045,225
• Time in Patent Office: 1,152 Days
• Field of Search: 370/441, 370/442, 370/341, 370/347, 370/535, 370/537, 370/342, 370/480, 370/205, 370/206, 370/208, 370/212-215, 375/245, 375/208, 375/209, 375/309, 329/112, 329/316, 329/300, 329/325, 329/336, 329/312, 329/330, 331/2, 455/206
• US Class Current: 370/480
• CPC Class Codes: H04L 5/02 Channels characterised by the type of signal

Abstract

A method and apparatus for simultaneously communicating a first data stream along with a second data stream. A first carrier is modulated with a first data stream and a feature of the modulated first carrier is then imposed under the control of a second independent data stream. The modulated first carrier with the imposed feature is then demodulated to provide the first data stream. The distinguishable feature of the modulated first carrier is then detected to provide the second data stream. The first and the second data streams are clocked at rates which are integer multiples of each other. The distinguishable feature of the modulated first carrier includes the amplitude of the modulated first carrier or the frequency of the modulated first carrier. M-ary information is transmitted by transmitting groups of 3 or more bits simultaneously by using distinguishable amplitude, frequency or time of occurrence values of a feature imposed on a first carrier.

Claims

1. A method of simultaneously providing in the same frequency band a first data stream along with other independent data streams, comprising the steps of:

modulating a first carrier with a first data stream to provide a modulated first carrier; and

imposing a distinguishable feature on the modulated first carrier to provide distinguishable values of a feature, which distinguishable values of the feature represent at least one other independent data stream, wherein said distinguishable feature includes times of occurrence.

2. The method of claim 1 further including:

transmitting the modulated first carrier with the distinguishable values of a feature through a transmission medium;

receiving the transmitted modulated first carrier with the distinguishable values of a feature to provide a received modulated first carrier with a feature;

demodulating the received modulated first carrier with distinguishable values of a feature to provide the first data stream; and

detecting the distinguishable values of a feature of the received modulated first carrier having distinguishable values of a feature to provide the other independent data streams.

3. The method of claim 1 including the step of clocking the data streams at rates which are integer multiples of each other.

4. A method of simultaneously providing in the same frequency band a first data stream along with other independent data streams, comprising the steps of:

modulating a first carrier with a first data stream to provide a modulated first carrier; and

using an auxiliary sinusoid to provide a distinguishable feature imposed on the modulated first carrier to provide distinguishable values of the feature of the modulated first carrier, which distinguishable values of the feature represent at least one other independent data stream, wherein said distinguishable feature includes time of occurrence.

5. The method of claim 4 including using the envelope values of a composite carrier formed by the first carrier combined with an auxiliary sinusoid to provide distinguishable values of a feature.

6. The method of claim 4 including using the frequency values of the composite carrier formed by the modulated first carrier combined with an auxilary sinusoid to form distinguishable values of a feature.

7. A data communication system for simultaneously communicating independent first and other data streams, comprising:

a modulator for modulating a first carrier with a first data stream to provide a modulated first carrier; and

means for imposing distinguishable values of a feature on the modulated first carrier to represent at least one other data stream, wherein said distinguishable values include time of occurrence.

8. The system of claim 7 further including:

a transmitter for transmitting the modulated first carrier with the distinguishable values of a feature imposed thereon through a transmission medium;

a receiver for receiving the transmitted modulated first carrier with the distinguishable values of a feature to provide a received modulated first carrier with the feature;

a demodulator for demodulating the received modulated first carrier with feature to provide a first output signal representing the first data stream; and

a detector for detecting the distinguishable values of a feature of the received modulated first carrier with feature to provide at least one other data stream.

9. The system of claim 7 wherein the first and other data streams are clocked at rates which are integer multiples of each other.

10. A method of simultaneously communicating a first data stream along with other data streams, comprising the steps of:

modulating a first carrier with a first data stream to provide a modulated first carrier;

imposing a distinguishable multi-valued feature on the modulated first carrier to provide distinguishable values of the feature, which values represent two or more other independent data streams;

wherein said distinguishable multi-valued feature includes time of occurrence;

transmitting the modulated first carrier with the distinguishable multi-valued feature through a transmission medium;

receiving the transmitted modulated first carrier with the distinguishable values of the multi-valued feature to provide a received modulated first carrier with said distinguishable values of the feature;

demodulating the received modulated first carrier with the distinguishable values to provide the first data stream; and

detecting the distinguishable values of the multi-valued feature to provide the two or more other independent data streams.

11. The method of claim 10 including the step of clocking the data streams at rates which are integer multiples of each other.

12. The method of claim 10 including the step of simultaneously transmitting M-ary information by simultaneously transmitting groups of 2 or more bits of the other independent data streams wherein each group of 2 or more bits defines a symbol and wherein the number of distinct symbols equals 2ⁿ where n is the number of bits.

13. A data communication system for simultaneously communicating an independent first and other data streams, comprising:

a modulator for modulating a first carrier with a first data stream to provide a modulated first carrier;

means for imposing a distinguishable multi-valued feature on the modulated first carrier to provide distinguishable values of the feature, which values represent two or more other independent data streams;

wherein said distinguishable multi-valued feature includes time of occurrence;

a transmitter for transmitting the modulated first carrier with distinguishable multi-valued feature through a transmission medium;

a receiver for receiving the transmitted modulated first carrier with the distinguishable values of the feature to provide a received modulated first carrier with said distinguishable values of the feature;

a demodulator for demodulating the received modulated first carrier to provide a first output signal representing the first data stream; and

a detector for detecting distinguishable values of the multi-value feature to provide two or more other independent data streams, wherein the multi-valued feature of the modulated first carrier which is used to represent the other data streams includes the time of occurrence of constructive and destructive interference conditions of the modulated first carrier.

14. The system of claim 13 wherein the first data stream and the other independent data streams are clocked at rates which are integer multiples of each other.

15. The data communication system of claim 13 including means for simultaneously transmitting M-ary information by simultaneously transmitting groups of 2 or more bits of the other independent data streams wherein each group of 2 or more bits defines a symbol and wherein the number of distinct symbols equals 2ⁿ where n is the number of bits.

16. A method for transmitting and receiving independent bit streams from two co-channel frequency-modulated carriers, comprising the steps of:

frequency modulating a first sinusoidal signal with a first input bit stream to provide a first frequency-modulated carrier signal;

identifying an input symbol associated with the binary state of a second bit stream;

frequency modulating a second sinusoidal signal with said identified input symbol to provide a second frequency-modulated carrier signal having selected values of amplitude and initial phase;

summing the first and the second frequency-modulated carrier signals to provide a combined transmitter signal;

frequency demodulating a replica of the combined transmitter signal to provide a frequency-demodulated signal, wherein the frequency-demodulated signal is comprised of the first input bit stream;

limiting the frequency-demodulated signal to provide an output signal corresponding to the first input bit stream;

detecting the spike characteristics including peak amplitude and position within a bit of the frequency-demodulated signal to provide an indication of the state of the input symbol;

converting the values of spike amplitude and position to binary states to provide an output symbol corresponding to the input symbol; and

wherein each of the multiple independent bit streams are recovered from the single composite power multiplexed sinusoidal carrier.

17. The method of claim 16 wherein the step of detecting the spike characteristics includes peak-voltage detecting and position detecting the voltage spikes of the frequency-demodulated signal.

18. The method of claim 16 wherein the input bit streams are clocked from a common timing reference signal in the transmitter.

19. The method of claim 18 wherein the input bit streams have data rates which are integer multiples of each other.

20. A system for transmitting and receiving independent bit streams from a composite modulated carrier, comprising:

a transmitter including;

a first system input terminal for receiving a first input bit stream;

a first frequency modulator including a numerically controlled oscillator coupled to the first system input terminal for receiving the first input bit stream and having an output terminal at which is provided a first sinusoidal signal of known initial phase, which sinusoidal signal is frequency modulated by the first input bit stream;

a summer having a first and second input terminal and an output terminal, wherein the output terminal of the first frequency modulator is coupled to the first input terminal of the summer;

other system input terminals for receiving the remaining input bit streams, which define the symbol to be transmitted;

a data register having output terminals and input terminals coupled to the other system input terminals;

logic circuitry having output terminals and input terminals coupled to the data register output terminals;

a second frequency modulator including a numerically controlled oscillator whose input terminals are coupled to the logic circuitry output terminals and having an output terminal at which is provided a second sinusoidal signal having values of initial phase and amplitude determined by the contents of the data register, which sinusoidal signal is frequency modulated by the output of the logic circuitry;

wherein the output terminal of the second frequency modulator is coupled to the second input terminal of the summer;

wherein the output signal of the summer is a composite carrier which is transmitted; and

wherein the power of the first sinusoidal signal is greater than the power of the second sinusoidal signal; and

a receiver, including;

an RF/IF amplifier having an output terminal at which is provided a replica of the transmitted composite carrier;

a frequency demodulator having an input terminal for receiving the output of the RF/IF amplifier, the frequency demodulator having an output terminal at which is provided a frequency-demodulated signal which is comprised of the bit stream on the stronger carrier on which are superimposed voltage spikes wherein said voltage spikes have characteristics which include amplitude, position and rate characteristics;

a limiter having an input terminal coupled to the output terminal of the frequency demodulator, said limiter having an output terminal at which is provided an output signal corresponding to the first input bit stream;

a detector having an input terminal coupled to the output terminal of the frequency demodulator for receiving the superimposed voltage spikes and measuring the times of occurrence of said voltage spikes, said detector having output terminals at which are provided the remaining bit streams; and

wherein the independent bit streams are recovered from a single composite transmitted carrier.

21. The system of claim 20 wherein the input bit streams are clocked from a common timing reference signal in the transmitter.

22. The system of claim 21 wherein the input bit streams have data rates which are integer multiples of each other.