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:
Oct. 27, 1998
Filed:
Mar. 20, 1996
Zulfiquar Sayeed, Philadelphia, PA (US);
Vijitha Weerackody, Watchung, NJ (US);
Lucent Technologies Inc., Murray Hill, NJ (US);
Abstract
A method and apparatus for performing adaptive hybrid automatic repeat request (ARQ) coding in which the coding is modified based on the acknowledgements returned by the receiver. In accordance with one illustrative embodiment of the present invention, the state of the channel is implicitly determined by the transmitter based upon the frequency of acknowledgments (ACKs and NACKs) arriving from the receiver. For example, since a NACK implies a weak received signal strength, the code rate of the FEC is advantageously reduced in response to such an acknowledgement. On the other hand, the code rate of the FEC is advantageously increased in response to an ACK. In accordance with another illustrative embodiment of the present invention, the acknowledgement returned by the receiver is modified to convey the number of errors in the corresponding received data packet. In particular, a Reed-Solomon (RS) outer code is employed in the FEC to enable the receiver to determine the number of errors in the received data packet. If the acknowledgement indicates a large number of errors at the receiver, the code rate of the FEC is advantageously reduced in response thereto.