# US 2016/0259062 A1 · Cell organization and transmission schemes in a wide area positioning system (waps) > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0259062 A1 - Document ID: US20160259062A1 - Status: Published application - Kind: A1 - Application number: 15/157,288 - Filed: 2016-05-17 - Published: 2016-09-08 - Earliest claimed: 2011-08-02 - Assignees: NextNav, LLC - Applicants: NextNav, LLC - Inventors: ARUN RAGHUPATHY; NORMAN F. KRASNER - Web page: https://patentgrep.com/patent/US20160259062A1 ## CPC - G01S 19/21: Interference related issues {; Issues related to cross-correlation, spoofing or other methods of denial of service} - G01S 19/05: providing aiding data - G01S 19/07: providing data for correcting measured positioning data, e.g. DGPS [differential GPS] or ionosphere corrections - G01S 19/11: wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters - G01S 19/45: by combining measurements of signals from the satellite radio beacon positioning system with a supplementary measurement - G01S 19/48: by combining or switching between position solutions derived from the satellite radio beacon positioning system and position solutions derived from a further system - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES ## Abstract A position location system comprises transmitters that broadcast positioning signals. Each broadcasted positioning signal comprises a pseudorandom ranging signal. The position location system includes a remote receiver that acquires and measures the time of arrival of the positioning signals received at the remote receiver. During an interval of time, at least two positioning signals are transmitted concurrently by the transmitters and received concurrently at the remote receiver. The two positioning signals have carrier frequencies offset from one another by an offset that is less than approximately twenty-five percent of the bandwidth of each positioning signal of the two positioning signals. Cross-interference between the positioning signals is reduced by tuning the remote receiver to a frequency of a selected signal of the two positioning signals and correlating the selected signal with a reference pseudorandom ranging signal matched to a transmitted pseudorandom ranging signal of the selected signal. ## Claims ### Claim 1 A method for transmitting positioning signals from a network of transmitters, the method comprising: transmitting, from each respective transmitter in a first set of n transmitters, a respective positioning signal using a respective carrier frequency that is the sum of a base frequency plus a respective offset frequency, wherein each respective offset frequency used for each respective transmitter is a product of a frequency multiplied by a respective fraction that is greater than or equal to 0/n and less than or equal to (n−1)/n, wherein the offset frequencies used for a first pair of adjacent transmitters that includes a first transmitter and a second transmitter from the first set of n transmitters differ by more than the product of the frequency multiplied by 1/n. ### Claim 2 (depends on 1) The method of claim 1, wherein the offset frequencies used for the first and second transmitters differ by less than the product of the frequency multiplied by (n−1)/n. ### Claim 3 (depends on 1) The method of claim 1, wherein the first and second transmitters are located in the network such that receivers traveling along a roadway receive positioning signals from both of the first and second transmitters. ### Claim 4 (depends on 3) The method of claim 3, wherein the receivers are permitted to travel along the roadway at a speed of 50 miles-per-hour or greater. ### Claim 5 (depends on 3) The method of claim 3, wherein the first and second transmitters are positioned such that receivers traveling along the roadway move towards the first transmitter while moving away from the second transmitter, or move away from the first transmitter while moving towards the second transmitter. ### Claim 6 (depends on 3) The method of claim 3, wherein a third transmitter from the first set of n transmitters is adjacent to the second transmitter and is located in the network such that receivers traveling along the roadway do not receive positioning signals from the third transmitter, and wherein the offset frequencies used for the second and third transmitters do not differ by more than the product of the frequency multiplied by 1/n. ### Claim 7 (depends on 1) The method of claim 1, wherein the offset frequencies used for a second pair of adjacent transmitters that includes a third transmitter and a fourth transmitter from the first set of n transmitters do not differ by more than the product of the frequency multiplied by 1/n. ### Claim 8 (depends on 7) The method of claim 7, wherein the third and fourth transmitters are positioned such that receivers cannot move towards one of the third and fourth transmitters while moving away from the other of the third and fourth transmitters at speeds of 50 miles-per-hour or greater. ### Claim 9 (depends on 7) The method of claim 7, wherein the third and fourth transmitters are positioned such that receivers can move towards one of the third and fourth transmitters while moving away from the other of the third and fourth transmitters at speeds no greater than a walking speed. ### Claim 10 (depends on 1) The method of claim 1, wherein the offset frequencies used for a second pair of adjacent transmitters that includes a third transmitter and a fourth transmitter from the first set of n transmitters do not differ by less than the product of the frequency multiplied by (n−1)/n. ### Claim 11 (depends on 10) The method of claim 10, wherein the third and fourth transmitters are positioned such that receivers cannot move towards one of the third and fourth transmitters while moving away from the other of the third and fourth transmitters at speeds of 50 miles-per-hour or greater. ### Claim 12 (depends on 10) The method of claim 10, wherein the third and fourth transmitters are positioned such that receivers can move towards one of the third and fourth transmitters while moving away from the other of the third and fourth transmitters at speeds no greater than a walking speed. ### Claim 13 (depends on 1) The method of claim 1, wherein n equals the integer 7. ### Claim 14 (depends on 1) The method of claim 1, wherein the offset frequencies used for each pair of adjacent transmitters from the first set of n transmitters are based on possible differential velocities of receivers traveling between the transmitters of that pair of adjacent transmitters. ### Claim 15 (depends on 1) The method of claim 1, wherein the offset frequencies used for each pair of adjacent transmitters from the first set of n transmitters are assigned to the transmitters of that pair of adjacent transmitters in order to minimize deleterious effects, as observed by receivers in the network, of Doppler shifted positioning signals transmitted from the transmitters of that pair of adjacent transmitters. ### Claim 16 (depends on 1) The method of claim 1, wherein the frequency is a frame rate of the positioning signals transmitted by the transmitters of the first set of n transmitters. ### Claim 17 (depends on 1) The method of claim 1, wherein each of the respective fractions are different, and are selected from the following fractions: 0/n, 1/n, . . . , (n−1)/n. ### Claim 18 (depends on 1) The method of claim 1, wherein the offset frequencies used for the first and second transmitters differ by at least the product of the frequency multiplied by 2/n. ### Claim 19 A non-transitory processor readable memory storing an application adapted to run on at least one processor to implement a method for transmitting positioning signals from a network of transmitters, the method comprising: transmitting, from each respective transmitter in a first set of n transmitters, a respective positioning signal using a respective carrier frequency that is the sum of a base frequency plus a respective offset frequency, wherein each respective offset frequency used for each respective transmitter is a product of a frequency multiplied by a respective fraction that is greater than or equal to 0/n and less than or equal to (n−1)/n, wherein the offset frequencies used for a first pair of adjacent transmitters that includes a first transmitter and a second transmitter from the first set of n transmitters differ by more than the product of the frequency multiplied by 1/n. ### Claim 20 A system for transmitting positioning signals from a network of transmitters, the system comprising: a first set of n respective transmitters that each transmit a respective positioning signal using a respective carrier frequency that is the sum of a base frequency plus a respective offset frequency, wherein each respective offset frequency used for each respective transmitter is a product of a frequency multiplied by a respective fraction that is greater than or equal to 0/n and less than or equal to (n−1)/n, wherein the offset frequencies used for a first pair of adjacent transmitters that includes a first transmitter and a second transmitter from the first set of n transmitters differ by more than the product of the frequency multiplied by 1/n.