11757777 (P.T.A.B. Feb. 27, 2014)

Ex Parte Ramesh et al

Patent Trial and Appeal BoardFeb 27, 2014

11757777 (P.T.A.B. Feb. 27, 2014)

UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 11/757,777 06/04/2007 Rajaram Ramesh 4015-5664 / P23219-US1 3286 24112 7590 02/27/2014 COATS & BENNETT, PLLC 1400 Crescent Green, Suite 300 Cary, NC 27518 EXAMINER MIAN, OMER S ART UNIT PAPER NUMBER 2461 MAIL DATE DELIVERY MODE 02/27/2014 PAPER Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte RAJARAM RAMESH, HAVISH KOORAPATY, and KUMAR BALACHANDRAN ____________ Appeal 2011-008571 Application 11/757,777 Technology Center 2400 ____________ Before MAHSHID D. SAADAT, CARLA M. KRIVAK, and JOHNNY A. KUMAR, Administrative Patent Judges. SAADAT, Administrative Patent Judge. DECISION ON APPEAL Appeal 2011-008571 Application 11/757,777 2 Appellants appeal under 35 U.S.C. § 134(a) from a final rejection of claims 1-31.1 We have jurisdiction under 35 U.S.C. § 6(b). We reverse. STATEMENT OF THE CASE Introduction Appellants’ invention relates to channel estimation in a transmit diversity environment. Multi-antenna transmission schemes are juxtaposed with transmit delay diversity transmissions that are relatively rich in pilot information and are used to improve channel estimation for the subsequent multi-antenna transmission (see Spec. ¶¶ [0001], [0009]). Independent claim 1, reproduced below, is representative of the subject matter on appeal. 1. A method of channel estimation for a signal having a first portion transmitted using a transmit delay diversity scheme and a second portion transmitted using another multi- antenna transmission scheme, the method comprising: determining a composite channel estimate for the first portion of the signal; determining first channel estimates for each subset of transmit antennas based on segregating the composite channel estimate into delay groups corresponding to time offsets of the transmit delay diversity scheme; and determining second channel estimates for each subset of transmit antennas as a function of corresponding ones of the first channel estimates for each subset of transmit antennas and as a function of pilot symbols received in the second portion of 1 In the Advisory Action, mailed Sep. 8, 2010, the Examiner objected to the finally rejected claims 6, 8, 19, and 21 as being dependent upon rejected base claims, but otherwise containing allowable subject matter. Appeal 2011-008571 Application 11/757,777 3 the signal, such that the corresponding ones of the first channel estimates for each subset of transmit antennas are used to improve estimation of the second channel estimates for each subset of transmit antennas for the second portion of the signal. Rejections on Appeal Claims 1-3, 5, 7, 9, 11-16, 18, 22, and 24-31 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Kadous (US 2005/0195763 A1) and Seki (US 2007/0263734 A1).2 (See Ans. 4-19). Claims 4 and 17 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Kadous, Seki, and Tao (US 2005/0052989 A1). (See Ans. 19-21). Claims 7 and 20 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Kadous, Seki, and Agrawal (US 2006/0013186 A1). (See Ans. 21-23). Claims 10 and 23 stand rejected under 35 U.S.C. § 103(a) as being unpatentable over Kadous, Seki, and Xing (US 2006/0120395 A1). (See Ans. 23-25). ANALYSIS In rejecting claim 1 over the combination of Kadous and Seki, the Examiner finds Kadous discloses all the claimed features except for the determining step related to the second channel estimates “as a function of corresponding ones of the first channel estimates for each subset of transmit 2 Seki (US 2007/0263734 A1) is the U.S. Patent Application Publication and the English version of WO 2006/082637, which was initially applied in the rejection. Appeal 2011-008571 Application 11/757,777 4 antennas and as a function of pilot symbols received in the second portion of the signal” for which the Examiner further relies on Seki (see Ans. 4-6). Appellants argue that, in contrast with the claimed “a signal having a first portion transmitted using a transmit delay diversity scheme and a second portion transmitted using another multi-antenna transmission scheme,” the channel estimations performed by the multiple-input single- output (MISO) and multiple-input multiple-output (MIMO) receivers of Kadous are based on using the same composite pilots (App. Br. 11-14; Reply Br. 6-7). Appellants specifically point out Kadous, in fact, discusses a multi-antenna transmission system supporting different receivers, but includes nothing to suggest that “two different multi-antenna transmission schemes are used” (Reply Br. 8 (emphasis omitted)). Appellants further contend Seki, while teaching a second channel estimation derived from a first channel estimation and additional pilot symbols, “makes no suggestion that these pilot symbols could or should be transmitted according to different multi-antenna transmission schemes” (Reply Br. 10).3 We agree with Appellants’ contentions above. Contrary to the Examiner’s position in response to Appellants’ arguments (Ans. 25-27), although paragraphs 120-23 of Kadous disclose transmitting the composite pilot using a delay diversity transmission scheme, nowhere in the reference is transmitting a different pilot using another multi-antenna transmission scheme discussed. The Examiner also takes the position that the MISO 3 We will not address Appellants’ additional arguments with respect to the other recited method steps in claim 1 because the issue of whether Kadous teaches “a signal having a first portion transmitted using a transmit delay diversity scheme and a second portion transmitted using another multi- antenna transmission scheme” is dispositive, as explained below. Appeal 2011-008571 Application 11/757,777 5 system in Kadous communicates the data portion of the signal using different sub-band allocation, which is not a MIMO scheme or a different multi-antenna scheme (Ans. 27). However, as stated by Appellants (Reply Br. 7-8), the term “transmitted according to a multi-antenna transmission scheme” is understood by one of ordinary skill in the art “to refer to a technique by which transmitted data or pilot symbols are mapped to multiple antennas for transmission over the air.” Therefore, we disagree with the Examiner that the difference in the way MISO and MIMO receivers may derive the channel estimates from the composite pilot in Kadous, or using the basic and additional pilot symbols in Seki, indicates that the composite pilot or pilot symbols are transmitted according to a transmit delay diversity scheme and another multi-antenna transmission scheme. CONCLUSION On the record before us, we find the Examiner erred in rejecting claim 1, as well as independent claims 14 and 29, which recite similar limitations, over the combination of Kadous and Seki. Therefore, since the Examiner has not identified any teachings in the other references, further applied in rejecting the dependent claims, which would have overcome the deficiencies discussed above with respect to claim 1, the 35 U.S.C. § 103 rejections of claims 1-5, 7, 9-18, 20, and 22-31 cannot be sustained. Appeal 2011-008571 Application 11/757,777 6 DECISION The Examiner’s decision rejecting claims 1-5, 7, 9-18, 20, and 22-31 is reversed. REVERSED bab