Patent SG-11201804655R-A (SG)
Title: In-band optical interference mitigation for direct-detection optical communication systems
Inventor: ZHOU XIANG
IPC: H04B10/69
Filed: 2016-12-20
Abstract: INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property Organization International Bureau IIIIII Hit II EH DID IIIII DEEM II III 11111111111111111111111111111R1111111 Frequency Offset Monk( xt — Ls:21 , FF find ...w that maximizes Z Decoder lett° Notch Filter Equalizer Photo Deteclori TA (10) International Publication Number WO 2017/120036 Al WIPO I PCT (43) International Publication Date 13 July 2017 (13.07.2017) AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DJ, DK, DM, DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, HN, HR, HU, ID, IL, IN, IR, IS, JP, KE, KG, KH, KN, KP, KR, KW, KZ, LA, LC, LK, LR, LS, LU, LY, MA, MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, OM, PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SA, SC, SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW. (84) Designated States (unless otherwise indicated, for every kind of regional protection available): ARIPO (BW, GH, GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, ST, SZ, TZ, UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, TJ, TM), European (AL, AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HR, HU, IE, IS, IT, LT, LU, LV, MC, MK, MT, NL, NO, PL, PT, RO, RS, SE, SI, SK, SM, TR), OAPI (BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, KM, ML, MR, NE, SN, TD, TG). Declarations under Rule 4.17: PCT/US2016/067797 (51) International Patent Classification: HO4B 10/69 (2013.01) (21) International Application Number: (22) International Filing Date: 20 December 2016 (20.12.2016) English English (25) Filing Language: (26) Publication Language: (30) Priority Data: 14/991,826 8 January 2016 (08.01.2016) US (71) Applicant: GOOGLE INC. [US/US]; 1600 Amphitheatre Parkway, Mountain View, California 94043 (US). (72) Inventors: ZHOU, Xiang; c/o Google Inc., 1600 Amphi- theatre Parkway, Mountain View, California 94043 (US). URATA, Ryohei; c/o Google Inc., 1600 Amphitheatre Parkway, Mountain View, California 94043 (US). MAO, Erji; c/o Google Inc., 1600 Amphitheatre Parkway, Moun- tain View, CA 94043 (US). LIU, Hong; c/o Google Inc., 1600 Amphitheatre Parkway, Mountain View, California 94043 (US). JOHNSON, Christopher Lyle; c/o Google Inc., 1600 Amphitheatre Parkway, Mountain View, Cali- fornia 94043 (US). (74) Agents: GORDON, Edward A. et al.; McDermott Will & Emery LLP, 500 North Capitol Street, N.W., Washington, District of Columbia 20001-1531 (US). (81) Designated States (unless otherwise indicated, for every kind of national protection available): AE, AG, AL, AM, as to applicant's entitlement to apply for and be granted a patent (Rule 4.17 (ii)) as to the applicant's entitlement to claim the priority of the earlier application (Rule 4.17(iii)) Published: with international search report (Art 21(3)) (54) Title: IN-BAND OPTICAL INTERFERENCE MITIGATION FOR DIRECT-DETECTION OPTICAL COMMUNICATION SYSTEMS W O 20 17 / 120036 Al (57) : This disclosure provides systems, methods, and apparatus for mitigating the effects of interference signals on optical signals received at a direct-detection optical receivers. The optical receivers are capable of attenuating interference noise signals res - ulting from the interference between a transmitted optical signal transmitted from a transmitter to the optical receiver and one or more additional signals received at the optical receiver. The interference can be due to multi-path interference or due to in-band in- terference. The receivers include a tunable filter for filtering the received optical signal to remove the interference. A frequency off- set module processes the received optical signal to determine a frequency offset indicative of the difference between the carrier fre- quencies of a modulated optical signal and an interference optical signal. The offset frequency and a bandwidth determined by the frequency offset module can be used to adjust the tunable filter to remove the interference signal from the received signal.