# US 2019/0356525 A1 · Method and apparatus for par reduction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0356525 A1 - Document ID: US20190356525A1 - Status: Published application - Kind: A1 - Application number: 16/476,978 - Filed: 2017-01-20 - Published: 2019-11-21 - Earliest claimed: 2017-01-20 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Gan WEN; Peng LIU - Web page: https://patentgrep.com/patent/US20190356525A1 ## CPC - H04L 27/2624: {by soft clipping} - H04L 5/1469: {using time-sharing} - H04L 27/08: Amplitude regulation arrangements - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Embodiments of the present disclosure provide an apparatus of reducing a peak-to-average ratio of a multi-carrier signal to be transmitted in a wireless communication system. The apparatus comprises a multi-carrier processing circuitry, a storage and a peak cancellation circuitry. The multi-carrier processing circuitry is configured to process a plurality of signals on respective carriers and to combine the processed plurality of signals into a multi-carrier signal to be transmitted. The multi-carrier processing circuitry is further configured to process an injected impulse to obtain an impulse response of the multi-carrier processing circuitry. The storage is configured to store the impulse response as a clipping pulse. The peak cancellation circuitry is configured to apply the clipping pulse to the multi-carrier signal to cancel a peak of the multi-carrier signal whose amplitude is over a predetermined threshold. ## Claims ### Claim 1 An apparatus of for reducing a peak-to-average ratio of a multi-carrier signal to be transmitted in a wireless communication system, comprising: multi-carrier processing circuitry configured to process a plurality of signals on respective carriers and to combine the processed plurality of signals into a multi-carrier signal to be transmitted, wherein the multi-carrier processing circuitry is further configured to process an injected impulse to obtain an impulse response of the multi-carrier processing circuitry; a storage configured to store the impulse response as a clipping pulse; and a peak cancellation circuitry configured to apply the clipping pulse to the multi-carrier signal to cancel a peak of the multi-carrier signal whose amplitude is over a predetermined threshold. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the multi-carrier processing circuitry is configured to: process the injected impulse within a first time period; process the plurality of signals within a second time period; and combine the processed plurality of signals within the second time period, and the peak cancellation circuitry is configured to apply the clipping pulse to the multi-carrier signal within the second time period. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the multi-carrier processing circuitry comprises a plurality of carrier processing branches each processing a different one of the plurality of signals on the respective carriers, and the impulse is injected to each of the plurality of carrier processing branches. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein each of the plurality of carrier processing branches comprises: a filtering circuit configured to filter the impulse with a preconfigured bandwidth; a delay aligning circuit configured to delay aligning the impulse with a preconfigured delay alignment coefficient; and a frequency translating circuit configured to frequency translate the impulse to a frequency of the corresponding carrier, and the multi-carrier processing circuitry comprises an adder configured to combine the impulses processed by the plurality of carrier processing branches to obtain the impulse response. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein each of the plurality of carrier processing branches further comprises: a gain adjusting circuit configured to adjust an amplitude of the impulse; and a rate converting circuit configured to convert the rate of the impulse with a preconfigured rate converting parameter. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein the preconfigured bandwidth, the preconfigured delay alignment coefficient, and the preconfigured rate converting parameter are configured according to the signal processed by the corresponding carrier processing branch. ### Claim 7 (depends on 5) The apparatus of claim 5, wherein the amplitude of the impulse is adjusted according to power spectrum densities of the plurality of signals on the respective carriers. ### Claim 8 (depends on 2) The apparatus of claim 2, wherein the wireless communication system is a time division duplex system, if the multi-carrier signal is transmitted in downlink from a base station to a terminal device, the first period is an uplink period for transmission from the terminal device to the base station, and if the multi-carrier signal is transmitted in uplink from the terminal device to the base station, the first period is a downlink period for transmission from the base station to the terminal device. ### Claim 9 (depends on 2) The apparatus of claim 2, wherein the wireless communication system is a frequency division duplex system, and the first period is an idle symbol period. ### Claim 10 A method of reducing a peak-to-average ratio of a multi-carrier signal to be transmitted in a wireless communication system, comprising: generating a clipping pulse by injecting an impulse to a multi-carrier processing system for processing a plurality of signals on respective carriers to obtain an impulse response of the multi-carrier processing system; storing the impulse response as the generated clipping pulse; processing, by the multi-carrier processing system, the plurality of signals on the respective carriers; combining, by the multi-carrier processing system, the processed plurality of signals into a multi-carrier signal to be transmitted; and applying the generated clipping pulse to the multi-carrier signal to cancel a peak of the multi-carrier signal whose amplitude is over a predetermined threshold. ### Claim 11 (depends on 10) The method of claim 10, wherein generating the clipping pulse is performed within a first time period; and processing the plurality of signals, combining the processed plurality of signals and applying the generated clipping pulse are performed within a second time period. ### Claim 12 (depends on 10) The method of claim 10, wherein the multi-carrier processing system comprises a plurality of carrier processing branches each processing a different one of the plurality of signals on the respective carriers, and injecting the impulse comprises injecting the impulse to each of the plurality of carrier processing branches. ### Claim 13 (depends on 12) The method of claim 12, wherein generating the clipping pulse comprises: processing the impulse at each of the plurality of carrier processing branches by at least: filtering the impulse by a filter with a preconfigured bandwidth, delay aligning the impulse with a preconfigured delay alignment coefficient, and frequency translating the impulse to a frequency of the corresponding carrier; and combining the impulses processed by the plurality of carrier processing branches. ### Claim 14 (depends on 13) The method of claim 13, wherein processing the impulse at each of the plurality of carrier processing branches further comprises: adjusting an amplitude of the impulse; and converting a rate of the impulse with a preconfigured rate converting parameter. ### Claim 15 (depends on 14) The method of claim 14, wherein the preconfigured bandwidth, the preconfigured delay alignment coefficient, and the preconfigured rate converting parameter are configured according to the signal processed by the corresponding carrier processing branch. ### Claim 16 (depends on 14) The method of claim 14, wherein the amplitude of the impulse is adjusted according to power spectrum densities of the plurality of signals on the respective carriers. ### Claim 17 (depends on 11) The method of claim 11, wherein the wireless communication system is a time division duplex system, if the multi-carrier signal is transmitted in downlink from a base station to a terminal device, the first period is an uplink period for transmission from the terminal device to the base station, and if the multi-carrier signal is transmitted in uplink from the terminal device to the base station, the first period is a downlink period for transmission from the base station to the terminal device. ### Claim 18 (depends on 11) The method of claim 11, wherein the wireless communication system is a frequency division duplex system, and the first period is an idle symbol period.