# US 8,787,499 B2 · Channel estimation with effective co-channel interference suppression > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,499 B2 - Document ID: US8787499B2 - Status: Granted - Kind: B2 - Application number: 12/055,745 - Filed: 2008-03-26 - Published: 2008-10-02 - Granted: 2014-07-22 - Earliest claimed: 2007-03-27 - Assignees: QUALCOMM Incorporated - Applicants: Peter Gaal; Tao Luo; Yongbin Wei - Inventors: Peter Gaal; Tao Luo; Yongbin Wei - Web page: https://patentgrep.com/patent/US8787499B2 ## CPC - H04L 27/2647: {Arrangements specific to the receiver only (equalisation H04L27/01)} - H04J 11/0056: {Inter-base station aspects} - H04L 25/0226: {sounding signals per se} - H04L 25/022: {of frequency response} - 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 method for a wireless communication system is provided. The method includes isolating a set of pilot signals, where the pilot signals are associated with multiple base stations or multiple sectors of a single base station. This includes nulling a subset of the pilot signals to mitigate co-channel interference and to perform channel estimation in accordance with at least one of the pilot signals. ## Claims ### Claim 1 A method, comprising: transforming received signals from a time domain to a frequency domain to generate a plurality of pilot signals and associated data in the frequency domain; nulling the associated data to isolate the plurality of pilot signals; converting the isolated plurality of pilot signals to the time domain; isolating a particular pilot signal in the time domain by zeroing each pilot signal of the isolated plurality of pilot signals except the particular pilot signal; and performing channel estimation using the particular pilot signal. ### Claim 2 (depends on 1) The method of claim 1, wherein each pilot signal of the plurality of pilot signals is associated with a different base station of multiple base stations. ### Claim 3 (depends on 1) The method of claim 1, further comprising: after isolating the particular pilot signal: analyzing the particular pilot signal from a particular base station or from a particular sector of a base station; and. ### Claim 4 (depends on 1) The method of claim 1, wherein performing the channel estimation comprises performing a time domain channel estimation or performing a frequency domain channel estimation. ### Claim 5 (depends on 1) The method of claim 1, further comprising transforming the particular pilot signal from the time domain to the frequency domain. ### Claim 6 (depends on 1) The method of claim 1, wherein the plurality of pilot signals is associated with three base stations. ### Claim 7 (depends on 1) The method of claim 1, wherein the plurality of pilot signals is associated with three sectors of a single base station. ### Claim 8 (depends on 1) The method of claim 1, wherein performing the channel estimation includes performing a tone extraction on the particular pilot signal or performing an inverse discrete Fourier transform on the particular pilot signal. ### Claim 9 (depends on 1) The method of claim 1, wherein performing the channel estimation includes performing a discrete Fourier transform on the particular pilot signal, performing a zero padding operation on the particular pilot signal, or performing a time domain interpolation filter operation on the particular pilot signal. ### Claim 10 A communications apparatus comprising: a processor; and a memory storing instructions executable by the processor to perform operations comprising: transforming received signals from a time domain to a frequency domain to generate a plurality of pilot signals and associated data in the frequency domain; nulling the associated data to isolate the plurality of pilot signals; converting the isolated plurality of pilot signals to the time domain; isolating a particular pilot signal in the time domain by zeroing each pilot signal of the isolated plurality of pilot signals except the particular pilot signal; and performing channel estimation using the particular pilot signal. ### Claim 11 (depends on 10) The communications apparatus of claim 10, wherein performing the channel estimation comprises performing a time domain channel estimation or performing a frequency domain channel estimation. ### Claim 12 (depends on 10) The communications apparatus of claim 10, wherein the processor comprises a tone extraction circuit to facilitate the channel estimation. ### Claim 13 (depends on 10) The communications apparatus of claim 10, wherein the processor comprises a zero padding circuit to facilitate the channel estimation. ### Claim 14 (depends on 10) The communications apparatus of claim 10, wherein the processor comprises a time domain interpolation filter to facilitate the channel estimation. ### Claim 15 (depends on 10) The communications apparatus of claim 10, wherein the processor comprises a thresholding component to facilitate the channel estimation. ### Claim 16 A communications apparatus comprising: means for transforming received signals from a time domain to a frequency domain to generate a plurality of pilot signals and associated data in the frequency domain; means for nulling the associated data to isolate the plurality of pilot signals; means for converting the isolated plurality of pilot signals to the time domain; means for isolating a particular pilot signal in the time domain by zeroing each pilot signal of the isolated plurality of pilot signals except the particular pilot signal; means for generating a channel estimate using the particular pilot signal; and means for transforming the channel estimate to the frequency domain for frequency domain processing. ### Claim 17 (depends on 16) The apparatus of claim 16, further comprising: means for analyzing the particular pilot signal from a particular base station or from a particular sector of a base station after isolating the particular pilot signal in the time domain. ### Claim 18 (depends on 16) The apparatus of claim 16, wherein zeroing each pilot signal of the isolated plurality of pilot signals except the particular pilot signal includes nulling each pilot signal of the isolated plurality of pilot signals in the time domain except the particular pilot signal. ### Claim 19 The apparatus 16, wherein each pilot signal of the plurality of pilot signals is associated with a different base station of multiple base stations. ### Claim 20 A non-transitory computer-readable medium comprising instructions that, when executed by a processor, cause the processor to, null data channels associated with orthogonal base stations or sectors to isolate a plurality of pilot tones isolate a single pilot tone from among the plurality of isolated pilot tones in a time domain by zeroing each pilot tone of the isolated plurality of pilot tones except the single pilot tone, wherein a subset of the isolated plurality of pilot tones is associated with a first transmission source and a second transmission source, and wherein the single pilot tone is associated with a third transmission source; and perform a channel estimation using the single pilot tone. ### Claim 21 (depends on 20) The non-transitory computer-readable medium of claim 20, wherein the channel estimation includes at least one of a time domain channel estimation or a frequency domain channel estimation. ### Claim 22 (depends on 20) The non-transitory computer-readable medium of claim 20, further comprising instructions that, when executed by the processor, cause the processor to transform the subset of the plurality of pilot tones to a frequency domain. ### Claim 23 An apparatus comprising: a processor; and a memory storing instructions executable by the processor to perform operations comprising: nulling data channels associated with orthogonal base stations or sectors to isolate a plurality of pilot signals; isolating a particular pilot signal of the isolated plurality of pilot signals in a time domain by zeroing each pilot signal of the isolated plurality of pilot signals except the particular pilot signal; performing channel estimation using the the particular pilot signal. ### Claim 24 (depends on 23) The apparatus of claim 23, wherein the operations further comprise transforming received signals from the orthogonal base stations or sectors to generate the plurality of pilot signals and data channels. ### Claim 25 (depends on 24) The apparatus of claim 24, wherein transforming the received signals includes a time domain to frequency domain transform. ### Claim 26 (depends on 23) The apparatus of claim 23, wherein the operations further comprise transforming the plurality of pilot signals from a frequency domain to the time domain.