# US 9,438,457 B2 · Peak to average power ratio suppression > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,438,457 B2 - Document ID: US9438457B2 - Status: Granted - Kind: B2 - Application number: 14/809,130 - Filed: 2015-07-24 - Published: 2015-11-19 - Granted: 2016-09-06 - Earliest claimed: 2013-03-25 - Assignees: MaxLinear, Inc. - Applicants: MaxLinear, Inc. - Inventors: Curtis Ling; Tim Gallagher; Elad Shaked - Web page: https://patentgrep.com/patent/US9438457B2 ## CPC - H04L 27/2614: {Peak power aspects} - H04L 27/2627: {Modulators} - H04J 2011/0009: {with FDM/FDMA} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) ## Abstract A transmitter comprises a first peak-to-average-power ratio (PAPR) suppression circuit, a second peak-to-average-power ratio (PAPR) suppression circuit, and a first modulator. The first PAPR suppression circuit may receive a first sequence of time-domain symbols to be transmitted, alter the first sequence based on each of a plurality of symbol ordering and/or inversion descriptors to generate a corresponding plurality of second sequences of time-domain symbols, measure a PAPR corresponding to each of the second sequences, select one of the plurality of symbol ordering and/or inversion descriptors based on the measurement of PAPR, and convey the selected one of the symbol ordering and/or inversion descriptors to the second PAPR suppression circuit. The second PAPR suppression circuit may receive the first sequence of time-domain symbols to be transmitted, and alter the first sequence based on the selected one of the symbol ordering and/or inversion descriptors to generate a reordered and/or inverted symbol sequence. ## Claims ### Claim 1 A system comprising: a first peak-to-average-power ratio (PAPR) suppression circuit, a second peak-to-average-power ratio (PAPR) suppression circuit, and a first modulator, wherein: said first PAPR suppression circuit is operable to: receive a first sequence of time-domain symbols to be transmitted; alter said first sequence based on each of a plurality of symbol ordering and/or inversion descriptors to generate a corresponding plurality of second sequences of time-domain symbols; measure a PAPR corresponding to each of said second sequences; select one of said plurality of symbol ordering and/or inversion descriptors based on said measurement of PAPR; and convey said selected one of said symbol ordering and/or inversion descriptors to said second PAPR suppression circuit; and said second PAPR suppression circuit is operable to: receive said first sequence of time-domain symbols to be transmitted; and alter said first sequence based on said selected one of said symbol ordering and/or inversion descriptors to generate a reordered and/or inverted symbol sequence; and said first modulator is operable to: modulate said reordered and/or inverted sequence onto one or more carriers. ### Claim 2 (depends on 1) The system of claim 1, wherein said first modulator is a carrier aggregation modulator. ### Claim 3 (depends on 1) The system of claim 1, wherein said first PAPR suppression circuit comprises a plurality of second modulators. ### Claim 4 (depends on 3) The system of claim 3, wherein each of said second modulators is operable to perform same operations as said first modulator using lower-resolution than said first modulator. ### Claim 5 (depends on 4) The system of claim 4, wherein said operations comprise: demultiplexing of a symbol sequence into a plurality of subsequences; and upconverting each of said plurality of subsequences to a different one of a plurality of frequency bands. ### Claim 6 (depends on 1) The system of claim 1, wherein said plurality of symbol ordering and/or inversion descriptors is selected from a larger set of possible symbol ordering and/or inversion descriptors. ### Claim 7 (depends on 1) The system of claim 1, wherein said selection is random. ### Claim 8 (depends on 1) The system of claim 1, wherein said selection is based on collected statistics regarding symbol ordering and/or inversion descriptors used for previous symbol sequences. ### Claim 9 (depends on 1) The system of claim 1, wherein said alteration of said first sequence based on said selected one of said symbol ordering and/or inversion descriptors comprises a reordering of symbols of said first sequence and/or a phase shift of one or more symbol of said first sequence. ### Claim 10 (depends on 1) The system of claim 1, wherein said first sequence of time-domain symbols comprises symbols from a plurality of symbol sources. ### Claim 11 A method comprising: in a transmitter comprising a first peak-to-average-power ratio (PAPR) suppression circuit, a second peak-to-average-power ratio (PAPR) suppression circuit, and a first modulator: receiving, by said first PAPR suppression circuit, a first sequence of time-domain symbols to be transmitted; altering, by said first PAPR suppression circuit, said first sequence based on each of a plurality of symbol ordering and/or inversion descriptors to generate a corresponding plurality of second sequences of time-domain symbols; measuring, by said first PAPR suppression circuit, a PAPR corresponding to each of said second sequences; selecting, by said first PAPR suppression circuit, one of said plurality of symbol ordering and/or inversion descriptors based on said measurement of PAPR; conveying, by said first PAPR suppression circuit, said selected one of said symbol ordering and/or inversion descriptors to said second PAPR suppression circuit; receiving, by said second PAPR suppression circuit, said first sequence of time-domain symbols to be transmitted; altering, by said second PAPR suppression circuit, said first sequence based on said selected one of said symbol ordering and/or inversion descriptors to generate a reordered and/or inverted symbol sequence; and modulating, by said first modulator, said reordered and/or inverted sequence onto one or more carriers. ### Claim 12 (depends on 11) The method of claim 11, wherein said first modulator is a carrier aggregation modulator. ### Claim 13 (depends on 11) The method of claim 11, wherein said first PAPR suppression circuit comprises a plurality of second modulators. ### Claim 14 (depends on 11) The method of claim 11, comprising: performing, by said first modulator, modulation operations using a first resolution; and performing, by each of said second modulators, said modulation operations using a second resolution that is lower than said first resolution. ### Claim 15 (depends on 14) The method of claim 14, wherein said operations comprise: demultiplexing a symbol sequence into a plurality of subsequences; and upconverting each of said plurality of subsequences to a different one of a plurality of frequency bands. ### Claim 16 (depends on 11) The method of claim 11, comprising selecting, by said first PAPR suppression circuit, said plurality of symbol ordering and/or inversion descriptors from a larger set of possible symbol ordering and/or inversion descriptors. ### Claim 17 (depends on 11) The method of claim 11, wherein said selecting is random. ### Claim 18 (depends on 11) The method of claim 11, wherein said selecting is based on collected statistics regarding symbol ordering and/or inversion descriptors used for previous symbol sequences. ### Claim 19 (depends on 11) The method of claim 11, wherein said altering said first sequence based on said selected one of said symbol ordering and/or inversion descriptors comprises reordering symbols of said first sequence and/or phase shifting one or more symbol of said first sequence. ### Claim 20 (depends on 11) The method of claim 11, wherein said first sequence of time-domain symbols comprises symbols from a plurality of symbol sources.