VSB receiver with complex equalization for improved multipath performance

• US 6,219,379 B1
• Filed: 11/17/1998
• Issued: 04/17/2001
• Est. Priority Date: 11/17/1998
• Status: Expired due to Term

• Current Assignee: Funai Electric Co., Ltd. (Funai Electric Holdings Company Limited)
• Original Assignee: Philips Electronics North America Corporation (Koninklijke Philips N.V.)
• Inventors: Ghosh, Monisha
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Corrielus, Jean B.
• Application Number:
  US09/193,430
• Time in Patent Office: 882 Days
• Field of Search: 375/229-236, 375/270, 375/277, 375/285, 375/321, 375/326, 375/346, 375/350, 375/365, 708/323, 708/322, 708/300, 708/819, 333/18, 333/28.R
• US Class Current: 375/232
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 5/211 Ghost signal cancellation H04N23/81 takes precedence

Abstract

A method and device for improving the reception of a vestigial-sideband (VSB) signal by reducing the loss of information at the band edges in severe multipath. This is achieved by using complex equalization in conjunction with real equalization, in which any band-edge distortion is equalized by the complex equalization.

Claims

1. A vestigial-sideband (VSB) receiver comprising:

an input for receiving a VSB signal which includes a field synch segment and band edges;

a complex equalizer for equalizing the band edges in the VSB signal;

a synch recovery circuit coupled to an output of the complex equalizer for recovering the field sync segment; and

a real equalizer for equalizing the remaining portion of the VSB signal.

2. The VSB receiver as claimed in claim 1, wherein the recovered field synch segment is used to train the complex equalizer.

3. The VSB receiver as claimed in claim 1 or 2, wherein said VSB receiver further comprises a blind adaptation circuit for blindly adapting the complex equalizer at least before the recovery of the field synch segment by the synch recovery circuit.

4. A vestigial-sideband (VSB) receiver comprising:

an input for receiving a VSB signal including band edges;

a composite equalizer comprising a forward section having an inner section with complex taps for equalizing band edges and an outer section with real taps for equalizing a remainder of the VSB signal, and a feedback section having real taps for equalizing a real output of the forward section.

5. A vestigial-sideband receiver comprising:

an input for receiving an up-converted VSB signal;

an A/D converter for A/D converting the up-converted VSB signal to a digital VSB signal;

a square-root-cosine filter for filtering the digital VSB signal;

a complex equalizer for equalizing band edges in the filtered digital VSB signal, said complex equalizer providing a real output;

a sync recovery unit for recovery of a field synch segment from the real output of the complex equalizer; and

a real equalizer for equalizing the real output of the complex equalizer.

6. A vestigial-sideband (VSB) receiver comprising:

an input for receiving an up-converted VSB signal;

an A/D converter for A/D converting the up-converted VSB signal to a digital VSB signal;

a square-root-cosine filter for filtering the digital VSB signal;

a composite forward equalizer having real and complex taps, the complex taps complex equalizing band edges of the filtered digital VSB signal, and the real taps equalizing a remaining portion of the filtered digital VSB signal, said composite forward equalizer having a real output;

a slicer for estimating the real output of the composite forward equalizer to the nearest symbol;

a feedback equalizer for equalizing an output of the slicer and for providing an equalized output;

an adder for adding the equalized output of the feedback equalizer and the real output of the composite forward equalizer forming a finalized equalizer output; and

a sync recovery unit for recovering a field sync segment from the finalized equalized output, an output of the sync recovery unit being used for adapting the taps of the composite forward equalizer.

7. A method of equalizing a vestigial-sideband (VSB) signal comprising the steps:

receiving the VSB signal which includes a field sync segment and band edges;

complex equalizing the band edges to provide a real output;

recovering the field sync segment from the real output;

real equalizing the real output; and

adapting the step of complex equalizing using the recovered field synch segment.