Adaptive equalizer with impulse noise protection

• US 5,692,010 A
• Filed: 01/17/1996
• Issued: 11/25/1997
• Est. Priority Date: 01/17/1996
• Status: Expired due to Term

• Current Assignee: Zenith Electronics Corporation (LG Corporation)
• Original Assignee: Zenith Electronics Corporation (LG Corporation)
• Inventors: Nielsen, Larry E.
• Primary Examiner(s): TSE, YOUNG TOI
• Application Number:
  US08/583,733
• Time in Patent Office: 678 Days
• Field of Search: 375/286, 375/287, 375/231, 375/232, 375/316, 375/346, 375/348, 375/350, 364/724.19, 364/724.2, 348/725, 348/729
• US Class Current: 375/232
• CPC Class Codes: H03K 5/1252 Suppression or limitation of noise or interference specially adapted for transmission systems H04B15/00, H04L25/08
• 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
• CPC Class Codes: H04N 5/213 Circuitry for suppressing or minimising impulsive noise for suppressing or minimising disturbance in image signal generation H04N23/81

Abstract

A digital receiver receives a multi level symbol signal that includes a frame sync. An equalizer is supplied with the signal and corrects for errors that are determined to exist therein on the basis of comparing the frame sync with a known value thereof or comparing the average level of the multi level symbols to an estimated (known) value thereof. A threshold circuit is included for rejecting impulse noise in the error signal that exceeds a threshold level that is higher than the maximum symbol level in the symbol.

Claims

1. A digital television receiver comprising:

means for receiving a multi level symbol signal;

means for developing an error signal indicative of impairments in said received multi level symbol signal;

means for compensating said error signal to nullify the effects of said impairments therein due to impulse noise;

means for supplying said compensated error signal for equalizing said received multi level symbol signal;

wherein said compensating means includes means for establishing a threshold for said received multi level symbol signal that is greater than the maximum symbol level in said received multi level symbol signal; and

means for nulling the effects of said impulse noise exceeding said threshold in said error signal.

2. The receiver of claim 1 wherein said received multi level symbol signal includes a frame sync and wherein said developing means develops said error signal based upon comparing said frame sync with a known value thereof.