Samuel K Lim

US Patent:

7856067, Dec 21, 2010

Filed:

Apr 4, 2007

Appl. No.:

11/732630

Inventors:

Charles C. Wang - Arcadia CA, US
Lan Xu - Cerritos CA, US
Samuel Lim - Los Angeles CA, US

Assignee:

The Aerospace Corporation - El Segundo CA

International Classification:

H04L 5/12
H04L 23/02

US Classification:

375261, 375265, 375241

Abstract:

Hierarchical modulation preferably uses a 16-ary quadrature amplitude modulation (QAM) modulator with a convolutional encoder that combine to effectively provide unequal protection to two different segments of streaming input data, with improved power efficiency with the same bandwidth efficiency, by encoding the first segment as coded data as LSBs as the second segment remains uncoded as uncoded MSBs, with the MSBs used for QAM constellation modest reliability interquadrant demodulation and detection, and with the LSBs used for low reliability intraquadrant detection, but with the LSBs subject to convolutional encoding and decoding rendering the LSBs with high reliability detection, such that, the two segments have unequal coding and modulation for providing unequal levels of reliability detection.

US Patent:

20050099322, May 12, 2005

Filed:

Nov 7, 2003

Appl. No.:

10/704393

Inventors:

S. Wainfan - Long Beach CA, US
Samuel Lim - Santa Monica CA, US
Richard Riley - Costa Mesa CA, US

International Classification:

G08G001/123

US Classification:

340995130, 701117000

Abstract:

A method and system for collecting and distributing vehicle traffic congestion information is disclosed. The method and system optionally involves deploying probe vehicles or other data sources for collecting and transmitting detailed traffic information which describes vehicle speeds actually being experienced along the routes of interest and transmitting all this information into a central computer at a central traffic data station, where the data are processed.