Kenneth W Shum

US Patent:

7474710, Jan 6, 2009

Filed:

Oct 3, 2003

Appl. No.:

10/532524

Inventors:

Ernest C. Chen - San Pedro CA, US
Jeng-Hong Chen - Temple City CA, US
Kenneth Shum - Monterey Park CA, US

Assignee:

The DIRECTV Group, Inc. - El Segundo CA

International Classification:

H03K 9/00

US Classification:

375316, 375340

Abstract:

An apparatus and method for receiving layered modulation signals is disclosed. A typical method includes receiving a layered modulation signal including an upper layer signal and a lower layer signal, demodulating and decoding the upper layer signal from the received layered modulation signal, estimating an upper layer amplitude factor and an upper layer phase factor from the received layered modulation signal. A substantially ideal upper layer signal is reconstructed from the demodulated and decoded upper layer signal including matching an ideal amplitude and an ideal phase by applying the upper layer amplitude factor and the upper layer phase factor to the reconstructed ideal upper layer signal. Finally, the reconstructed ideal upper layer signal is subtracted from the received layered modulation signal to produce the lower layer signal for processing.