The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 13, 2012
Filed:
Jul. 05, 2005
Ravi Palanki, San Diego, CA (US);
Aamod Khandekar, San Diego, CA (US);
Ravi Palanki, San Diego, CA (US);
Aamod Khandekar, San Diego, CA (US);
Q1UALCOMM Incorporated, San Diego, CA (US);
Abstract
A transmitter generates a pilot having a constant time-domain envelope and a flat frequency spectrum based on a polyphase sequence. To generate a pilot IFDMA symbol, a first sequence of pilot symbols is formed based on the polyphase sequence and replicated multiple times to obtain a second sequence of pilot symbols. A phase ramp is applied to the second pilot symbol sequence to obtain a third sequence of output symbols. A cyclic prefix is appended to the third sequence of output symbols to obtain an IFDMA symbol, which is transmitted in the time domain via a communication channel. The pilot symbols may be multiplexed with data symbols using TDM and/or CDM. A pilot LFDMA symbol may also be generated with a polyphase sequence and multiplexed using TDM or CDM. A receiver derives a channel estimate based on received pilot symbols and using minimum mean-square error, least-squares, or some other channel estimation technique.