Low power radio communication system
A method significantly reduces the average power for radio communication in a communication system, such as a system that has applications requiring low communication latency. The method may use a low power radio communication circuit (e.g., a non-heterodyne receiver) to wait for a communication request, taking advantage of the low power consumption of the radio communication circuit. Subsequent to receiving and validating the communication request, the communication system may switch to a more efficient—but higher power—communication circuit. Thus, effective communication is achieved without making undesirable tradeoffs, such as reduced sensitivity.
1. A radio communication system, comprising a first radio communication device, which comprises:
a first communication circuit comprising a non-heterodyne receiver, configured to receive a communication request and to provide a wake-up signal upon receiving the communication request; and
a second communication circuit comprising a receiver, a transmitter, or a transceiver, having an operating state and a power saving state, wherein said second communication circuit switches from the power saving state to the operating state upon receiving the wake-up signal from the non-heterodyne receiver, wherein the non-heterodyne receiver is capable of demodulating and decoding the communication request, the communication request being provided in a composite signal; and wherein the non-heterodyne receiver includes multiple detector stages; the composite signal comprising an energy sense (CW) modulation technique, followed by modulation using two or more of the following modulation techniques:
a. amplitude-modulation (AM)
b. single tone modulation;
c. digital data encoding using at least one of: amplitude-shift keying (ASK); On-Off Keying (OOK); frequency-shift keying (FSK); pulse code modulation (PCM); pseudorandom-noise (PN-Code) technique using on-off keying (OOK) or amplitude-shift keying (ASK);
d. multiple tones in time sequence;
e. multiple tones at the same time;
wherein at least one of the two or more modulation techniques includes said digital data encoding.
2. A radio communication system as in claim 1 , wherein said energy sense (CW) modulation technique occurs at a first frequency, which is a carrier frequency.
3. A radio communication system as in claim 1 , wherein said energy sense (CW) modulation technique occurs at a first frequency, which is a subcarrier frequency.
4. A radio communication system as in claim 1 , wherein said energy sense (CW) modulation technique occurs at a first frequency, followed by a second energy sense (CW) modulation technique which occurs at a second frequency, wherein said first and second frequencies include a carrier frequency and a sub-carrier frequency.
5. A radio communication system as in claim 1 , wherein said composite signal further includes a data stream.
6. A radio communication system as in claim 1 , wherein the two or more modulation techniques include pulse code modulation (PCM).
7. A radio communication system as in claim 1 , wherein the digital data encoding encodes at least one of the elements in the group consisting of a distinct receiver identifier and a distinct transmitter identifier.
8. A radio communication system as in claim 1 , wherein the digital data encoding encodes one or more of the following: a device type, or a purpose of communication, or a context information.
9. A radio communication system as in claim 1 , wherein the digital data encoding encodes error detection or error correction codes.
10. A radio communication system as in claim 9 , wherein the error correction codes comprise forward error correction (FEC) codes.
11. In a radio communication device, a method comprising:
receiving, using a non-heterodyne receiver, a communication request;
providing a wake-up signal upon detecting the communication request; and
switching a second communication circuit from a power saving state to an operating state upon receiving the wake-up signal from the non-heterodyne receiver, the method further comprising using the non-heterodyne receiver for demodulating and decoding the communication request, the communication request being provided in a composite signal; and wherein the non-heterodyne receiver includes multiple detector stages; the composite signal comprising an energy sense (CW) modulation technique, followed by modulation using two or more of the following modulation techniques:
a. amplitude-modulation (AM);
b. single tone modulation;
c. digital data encoding using at least one of: amplitude-shift keying (ASK); On-Off Keying (OOK); frequency-shift keying (FSK); pulse code modulation (PCM); pseudorandom-noise (PN-Code) technique using on-off keying (OOK) or amplitude-shift keying (ASK);
d. multiple tones in time sequence;
e. multiple tones at the same time;
wherein at least one of the two or more modulation techniques includes said digital data encoding.
12. A method as in claim 11 , wherein said energy sense (CW) modulation technique occurs at a first frequency, which is a carrier frequency.
13. A method as in claim 11 , wherein said energy sense (CW) modulation technique occurs at a first frequency, which is a subcarrier frequency.
14. A method as in claim 11 , wherein said energy sense (CW) modulation technique occurs at a first frequency, followed by a second energy sense (CW) modulation technique which occurs at a second frequency, wherein said first and second frequencies include a carrier frequency and a sub-carrier frequency.
15. A method as in claim 11 , wherein said composite signal further includes a data stream.
16. A method as in claim 11 , wherein the two or more modulation techniques include pulse code modulation (PCM).
17. A method as in claim 11 , wherein the digital data encoding encodes a distinct receiver identifier.
18. A method as in claim 11 , wherein the digital data encoding encodes one or more of the following: a device type, or a purpose of communication, or a context information.