# US 11,122,407 B1 · Compressive sensing in LPWAN communications with transmission mapping > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,122,407 B1 - Document ID: US11122407B1 - Status: Granted - Kind: B1 - Application number: 17/238,374 - Filed: 2021-04-23 - Granted: 2021-09-14 - Earliest claimed: 2020-07-31 - Assignees: King Abdulaziz University - Applicants: King Abdulaziz University - Inventors: Abdulah Aljohani; Waleed Alasmary - Web page: https://patentgrep.com/patent/US11122407B1 ## CPC - H03M 13/6306: {Error control coding in combination with Automatic Repeat reQuest [ARQ] and diversity transmission, e.g. coding schemes for the multiple transmission of the same information or the transmission of incremental redundancy (H03M13/3761, H03M13/3769 and H03M13/635 take precedence)} - H04W 4/70: Services for machine-to-machine communication [M2M] or machine type communication [MTC] - H03M 13/1575: {Direct decoding, e.g. by a direct determination of the error locator polynomial from syndromes and subsequent analysis or by matrix operations involving syndromes, e.g. for codes with a small minimum Hamming distance} - H03M 13/19: Single error correction without using particular properties of the cyclic codes, e.g. Hamming codes, extended or generalised Hamming codes - H04B 1/69: Spread spectrum techniques - H04L 1/0042: {Encoding specially adapted to other signal generation operation, e.g. in order to reduce transmit distortions, jitter, or to improve signal shape (H04L1/0067 takes precedence)} - H04L 1/0061: {Error detection codes} - H04W 4/38: for collecting sensor information - H04W 4/40: for vehicles, e.g. vehicle-to-pedestrians [V2P] - H04W 80/02: Data link layer protocols - H04W 84/18: Self-organising networks, e.g. ad-hoc networks or sensor networks - H03M 13/27: using interleaving techniques - H04B 2001/6912: {using chirp} - H04L 1/0057: {Block codes (H04L1/0061, H04L1/0064 take precedence)} - H04L 1/0071: {Use of interleaving (interleaving per se H03M13/27)} - Y02D 30/70: in wireless communication networks - H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04B: TRANSMISSION - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract A LoRa device for communicating sensor signals in a low power wide area network (LPWAN) includes a physical layer using Hamming encoding and Gray indexing with chirp spread signal (CSS) modulation to encode and modulate the sensor signals and a medium access layer (MAC) including a compressive sensing sub-layer which reduces encoded, modulated signals to sparse vectors. A transmission packet is formed by combining the sparse vectors with a selected set of sparse vectors representing past measurements and the incoming velocity of the sensor signals. A receiver decompresses the transmission packet by reconstructing, at a sparse recovery sub-layer of a receiver MAC layer, the encoded, modulated sensor signals. A decoder path removes the CSS modulation and Gray indexing, and Hamming decodes the sensors signals. ## Claims ### Claim 1 A method for compressive sensing based communications of low range (LoRa) devices in a low power wide area network (LPWAN) with differential phase shift keying mapping, comprising: receiving, by a physical layer of a LoRa device, a bit stream of sensor measurements from at least one sensor selected from the group consisting of an accelerometer, an altimeter, and a temperature sensor; a GPS module and an antenna at an incoming velocity; encoding the bit stream to generate an encoded bit stream; modulating the encoded bit stream by chirp spread spectrum modulation to generate a chirp modulated encoded bit stream; forming a first transmission packet including at least a preamble, the chirp modulated encoded bit stream and a cyclic redundancy check (CRC); receiving the first transmission packet by a multiple access layer (MAC) of the LoRa device; compressing the chirp modulated encoded bit stream of the first transmission packet into sparse vectors; combining the sparse vectors with a linear combination of a randomly selected set of sparse vectors representing past measurements and the in-coming velocity of the bit stream to generate a payload; forming a second transmission packet including the preamble, the payload and the cyclic redundancy check; mapping the second transmission packet to in-phase and quadrature transmission paths with a differential phase shift keying (DQPSK) mapper; and transmitting the second transmission packet through the antenna according to the mapping at a randomly selected time. ### Claim 2 (depends on 1) The method of claim 1, further comprising: encoding the bit stream by: encoding the bits with a Hamming encoder, by using Hamming forward error correction to form a first coded bit sequence; interleaving the first coded bit sequence to form a second coded bit sequence; and applying Gray indexing to the second coded bit sequence to prevent off-by-one errors when resolving symbols to generate a third coded bit sequence. ### Claim 3 (depends on 2) The method of claim 2, further comprising: modulating the encoded bit stream by combining the third coded bit sequence with a base chirp signal generated by a local oscillator at a chirp rate. ### Claim 4 (depends on 3) The method of claim 3, further comprising: selecting a channel bandwidth from the group consisting of 125 kHz, 250 kHz and 500 kHz; matching a coding rate to a channel coding rate, wherein the coding rate is selected from R c = 4 4 + n where n={1, 2, 3, 4}; and encoding the signal bits by using Hamming forward error correction at the coding rate. ### Claim 5 (depends on 4) The method of claim 4, further comprising: compressing the chirp modulated encoded bit stream of the first transmission packet into sparse vectors by retaining only non-zero values of the sparse vectors. ### Claim 6 (depends on 1) The method of claim 1, further comprising: transmitting the second transmission packet according to a Class A protocol, in which the LoRa device sleeps until it wakes for transmission at the randomly selected time.