# US 11,115,254 B2 · Method for determining reserved tones and transmitter for performing PAPR reduction using tone reservation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,115,254 B2 - Document ID: US11115254B2 - Status: Granted - Kind: B2 - Application number: 16/996,191 - Filed: 2020-08-18 - Published: 2020-12-03 - Granted: 2021-09-07 - Earliest claimed: 2015-06-09 - Assignees: Samsung Electronics Co., Ltd. - Applicants: Samsung Electronics Co., Ltd. - Inventors: Joo-sung Park; Young-ho Oh - Web page: https://patentgrep.com/patent/US11115254B2 ## CPC - H04L 27/262: {Reduction thereof by selection of pilot symbols} - H04B 1/04: Circuits - H04L 5/0007: {the frequencies being orthogonal, e.g. OFDM(A) or DMT} - H04L 5/0048: {Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091)} - H04L 27/2618: {Reduction thereof using auxiliary subcarriers} - H04L 27/2628: {Inverse Fourier transform modulators, e.g. inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators (H04L27/2634 takes precedence)} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04B: TRANSMISSION ## Abstract A method of determining reserved tones for reduction of a peak to average power ratio (PAPR) includes: selecting carrier indices for the reserved tones and generating a kernel signal based on the selected carrier indices; calculating a comparison reference average value of the kernel signal, selecting one of the calculated comparison reference average value and a prestored comparison reference average value, and preliminarily determining carrier indices of the reserved tones based on the selection; re-arranging an order of the preliminarily determined carrier indices; calculating a comparison reference average value of a kernel signal generated, whenever each of the re-arranged carrier indices is changed to another carrier index, to generate a plurality of comparison reference average values, and finally determining carrier indices of the reserved tones which generates a kernel signal having the smallest comparison reference average value among the comparison reference average values as the indices of the reserved tones. ## Claims ### Claim 1 A receiving apparatus comprising: a processor configured to process a frame received from a transmitting apparatus based on positions of reserved tones of an orthogonal frequency division multiplexing (OFDM) symbol for a peak to average power ratio (PAPR) reduction, wherein a fast fourier transform (FFT) size of the OFDM symbol is 16K, and wherein the positions of reserved tones are represented by a set of carriers having carrier indices listed below: FFT Size (Number of Reserved Tones) Carrier Indices 16K (144) 421, 548, 589, 621, 644, 727, 770, 813, 857, 862, 1113, 1187, 1201, 1220, 1393, 1517, 1821, 1899, 1924, 2003, 2023, 2143, 2146, 2290, 2474, 2482, 2597, 2644, 2749, 2818, 2951, 3014, 3212, 3237, 3363, 3430, 3515, 3517, 3745, 3758, 4049, 4165, 4354, 4399, 4575, 4763, 4789, 4802, 4834, 4970, 5260, 5386, 5395, 5402, 5579, 5716, 5734, 5884, 5895, 6073, 6123, 6158, 6212, 6243, 6521, 6593, 6604, 6607, 6772, 6842, 6908, 6986, 7220, 7331, 7396, 7407, 7588, 7635, 7665, 7893, 7925, 7949, 8019, 8038, 8167, 8289, 8295, 8338, 8549, 8555, 8660, 8857, 8925, 9007, 9057, 9121, 9364, 9375, 9423, 9446, 9479, 9502, 9527, 9860, 9919, 9938, 10138, 10189, 10191, 10275, 10333, 10377, 10988, 11109, 11261, 11266, 11362, 11390, 11534, 11623, 11893, 11989, 12037, 12101, 12119, 12185, 12254, 12369, 12371, 12380, 12401, 12586, 12597, 12638, 12913, 12974, 13001, 13045, 13052, 13111, 13143, 13150, 13151, 13300. ### Claim 2 (depends on 1) The receiving apparatus as claimed in claim 1, wherein the OFDM symbol is one of a plurality of OFDM symbols included in a frame, and wherein the frame includes a preamble symbol, subframe boundary symbols, and data symbols. ### Claim 3 (depends on 2) The receiving apparatus as claimed in claim 2, wherein the carrier indices of the set of carriers comprise carrier indices, when a position in the preamble symbol into which a preamble pilot is inserted and a position in the subframe boundary symbols into which a subframe boundary pilot is inserted are defined based on a pilot insertion pattern, and an edge pilot is inserted into a first carrier and a last carrier in each of the subframe boundary symbols. ### Claim 4 (depends on 3) The receiving apparatus as claimed in claim 3, wherein the pilot insertion pattern is determined based on Dx=6, 12, 16, 24, 32, and wherein the Dx is a difference of carrier indices between adjacent carriers into which a pilot is to be inserted. ### Claim 5 (depends on 2) The receiving apparatus as claimed in claim 2, wherein the carrier indices of the set of carriers comprise carrier indices, when a position in the data symbols into which a scattered pilot is inserted is defined based on a pilot insertion pattern, and an edge pilot is inserted into a first carrier and a last carrier in each of the data symbols. ### Claim 6 (depends on 5) The receiving apparatus as claimed in claim 5, wherein the pilot insertion pattern is determined based Dx=3, 4, 6, 8, 12, 16, 24, 32, and wherein the Dx is a difference of carrier indices between adjacent carriers into which a pilot is inserted. ### Claim 7 (depends on 5) The receiving apparatus as claimed in claim 5, wherein the pilot insertion pattern is determined based Dy=2, 4, and wherein the Dy is a difference of symbol indices between successive pilots on a specific carrier. ### Claim 8 (depends on 1) The receiving apparatus as claimed in claim 1, wherein the OFDM symbol comprises a plurality of symbols comprising a preamble symbol, subframe boundary symbols, and data symbols, and wherein the carrier indices are determined based on a pattern of pilots inserted into the plurality of symbols. ### Claim 9 A transmitter comprising at least one processor to implement: a pilot inserter configured to insert pilots into first carriers of an orthogonal frequency division multiplexing (OFDM) symbol; and a peak to average power ratio (PAPR) reducer configured to generate a signal for reducing the PAPR of the OFDM symbol, wherein a fast fourier transform (FFT) size of the OFDM symbol is 16K, and wherein the PAPR reducer is configured to generate the signal for reducing the PAPR of the OFDM symbol using a set of second carriers having carrier indices listed below: FFT Size (Number of Reserved Tones) Carrier Indices 16K 421, 548, 589, 621, 644, 727, 770, 813, 857, 862, 1113, 1187, 1201, (144) 1220, 1393, 1517, 1821, 1899, 1924, 2003, 2023, 2143, 2146, 2290, 2474, 2482, 2597, 2644, 2749, 2818, 2951, 3014, 3212, 3237, 3363, 3430, 3515, 3517, 3745, 3758, 4049, 4165, 4354, 4399, 4575, 4763, 4789, 4802, 4834, 4970, 5260, 5386, 5395, 5402, 5579, 5716, 5734, 5884, 5895, 6073, 6123, 6158, 6212, 6243, 6521, 6593, 6604, 6607, 6772, 6842, 6908, 6986, 7220, 7331, 7396, 7407, 7588, 7635, 7665, 7893, 7925, 7949, 8019, 8038, 8167, 8289, 8295, 8338, 8549, 8555, 8660, 8857, 8925, 9007, 9057, 9121, 9364, 9375, 9423, 9446, 9479, 9502, 9527, 9860, 9919, 9938, 10138, 10189, 10191, 10275, 10333, 10377, 10988, 11109, 11261, 11266, 11362, 11390, 11534, 11623, 11893, 11989, 12037, 12101, 12119, 12185, 12254, 12369, 12371, 12380, 12401, 12586, 12597, 12638, 12913, 12974, 13001, 13045, 13052, 13111, 13143, 13150, 13151, 13300. ### Claim 10 (depends on 9) The transmitter as claimed in claim 9, wherein the OFDM symbol is one of a plurality of OFDM symbols included in a frame, and wherein the frame includes a preamble symbol, subframe boundary symbols, and data symbols. ### Claim 11 (depends on 10) The transmitter as claimed in claim 10, wherein the carrier indices of the set of second carriers comprise carrier indices, when a position in the preamble symbol into which a preamble pilot is inserted and a position in the subframe boundary symbols into which a subframe boundary pilot is inserted are defined based on a pilot insertion pattern, and an edge pilot is inserted into a first carrier and a last carrier in each of the subframe boundary symbols. ### Claim 12 (depends on 11) The transmitter as claimed in claim 11, wherein the pilot insertion pattern is determined based on Dx=6, 12, 16, 24, 32, and wherein the Dx is a difference of carrier indices between adjacent carriers into which a pilot is to be inserted. ### Claim 13 (depends on 10) The transmitter as claimed in claim 10, wherein the carrier indices of the set of second carriers comprise carrier indices, when a position in the data symbols into which a scattered pilot is inserted is defined based on a pilot insertion pattern, and an edge pilot is inserted into a first carrier and a last carrier in each of the data symbols. ### Claim 14 (depends on 13) The transmitter as claimed in claim 13, wherein the pilot insertion pattern is determined based Dx=3, 4, 6, 8, 12, 16, 24, 32, and wherein the Dx is a difference of carrier indices between adjacent carriers into which a pilot is inserted. ### Claim 15 (depends on 13) The transmitter as claimed in claim 13, wherein the pilot insertion pattern is determined based Dy=2, 4, and wherein the Dy is a difference of symbol indices between successive pilots on a specific carrier.