ZCNET—power wide area network (LPWAN) code division multiplexing (CDM) and modulation system, process, computer program product, and circuitry
View Patent ↗A novel LPWAN technology includes a ZCNET node that transmit signals that occupy a very small fraction of the signal space, resulting in very low collision probabilities. ZCNET supports parallel root channels within a single frequency channel by using Zadoff-Chu (ZC) root sequences. The root channels do not severely interfere with each other, because the interference power is spread evenly over the entire signal space. ZCNET has its node randomly choose the transmission channel and range, while still achieving high packet receiving ratios such as 0.9 or above, because the load in each root channel is small.
1. An access point device, comprising:
circuitry configured to:
transmit to a node device using a frequency band having a plurality of available parallel root channels associated to the frequency band;
randomly select a root channel from the plurality of available parallel root channels;
randomly select a number of consecutive points of a signal vector from the selected root channel location for transmission of a packet; and
send the packet by transmitting peaks, at the selected root channel location, that are a sum of signal vectors for peak locations.
2. The access point device of claim 1 , wherein the circuitry is further configured to determine the peak locations according to a codeword, a range inside the signal vector, and the root channel.
3. The access point device of claim 1 , wherein the circuitry is further configured to transmit a beacon packet.
4. The access point device of claim 1 , wherein a number of the plurality of available parallel root channels is eight.
5. The access point device of claim 1 , wherein:
the circuitry is further configured to modulate data by transmitting one Zadoff-Chu sequence that is derived from one of eight root sequences; and
each root sequence generates a root channel.
6. The access point device of claim 1 , wherein:
the circuitry is further configured to modulate data by transmitting a plurality of Zadoff-Chu sequences;
each Zadoff-Chu sequence is derived from one of eight root sequences; and
each root sequence generates a root channel.
7. The access point device of claim 1 , wherein the circuitry is further configured to transmit a transmitted peak at one of four candidate peak locations.
8. The access point device of claim 7 , wherein the circuitry is further configured to transmit the transmitted peak at one out of four candidate phase values.
9. The access point device of claim 1 , wherein the circuitry is further configured to determine locations and phases of the transmitted peaks according to codewords.
10. The access point device of claim 1 , wherein:
the packet includes a preamble including consecutive time symbols; and
each consecutive time symbol has a peak at a location from an offset value to a starting location of a subset range.
11. The access point device of claim 10 , wherein the offset value is calculated according to a mathematical formula known to both the access point device and the node device.
12. The access point device according to claim 10 , wherein the peaks of the consecutive time symbols of the preamble notify node device signal detection circuitry of the sending of the packet by producing an alignment at node device signal detection circuitry indicating a higher peak relative to other possible signals.
13. A node device, comprising:
control circuitry configured to:
detect a signal in a frequency band having a plurality of available parallel root channels associated to the frequency band; wherein:
the signal includes a root channel from the plurality of available root channels of the frequency band; and
the signal is in a subset range in a range of a signal vector of the root channel; and
receive a packet via the signal by detecting peaks at a selected root channel location, wherein the detecting the peaks comprises detecting the peaks by receiving a signal vector at the selected root channel location.
14. The node device of claim 13 , wherein the detected peaks are at one out of four candidate peak locations.
15. The node device of claim 14 , wherein a phase of the detected peaks is at one of four candidate phase values.
16. The node device of claim 15 , wherein:
the packet includes a preamble including consecutive time symbols; and
each consecutive time symbol has a peak at a location from an offset value to a starting location of a subset range.
17. The node device of claim 16 , wherein the offset value is a number calculated according to a mathematical formula known to the node device.
18. The node device of claim 17 , wherein the peaks of the consecutive time symbols of the preamble produce an alignment at node device detection circuitry to indicate a higher peak relative to other signals in the frequency band, thereby notifying the signal detection circuitry of the detection of the packet.
19. The node device of claim 13 , wherein the control circuitry is further configured to use a simple interference cancellation procedure to improve packet reception.
20. A data reception procedure, comprising:
detecting a signal in a frequency band having a plurality of available parallel root channels associated to the frequency band, wherein:
the signal includes a root channel from the plurality of available root channels; and
the signal is in a subset range in a range of a signal vector of the root channel; and
receiving a packet via the signal by detecting peaks at a selected root channel location, wherein the detecting the peaks comprises detecting the peaks by receiving a signal vector at the selected root channel location.