Digital broadcast receiving apparatus

• US 7,486,940 B2
• Filed: 03/15/2004
• Issued: 02/03/2009
• Est. Priority Date: 03/17/2003
• Status: Expired due to Fees

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Kageyama, Sadashi, Yasuho, Takeo, Kato, Hisaya, Ozeki, Hiroaki
• Primary Examiner(s): Nguyen; Duc M
• Application Number:
  US10/528,307
• Publication Number:
  US 20060018286A1
• Time in Patent Office: 1,786 Days
• Field of Search: 455/272, 455/277.1, 455/277.2, 455/232.1, 455/234.1, 455/245.1, 455/245.2, 455/247.1, 455/250.1
• US Class Current: 455/234.1
• CPC Class Codes: H04B 7/0802 using antenna selection H04B7/0868 takes precedence; antenna beam directivity switching H01Q3/24
• CPC Class Codes: H04B 7/0814 based on current reception conditions, e.g. switching to different antenna when signal level is below threshold
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04H 20/28 Arrangements for simultaneous broadcast of plural pieces of information
• CPC Class Codes: H04H 40/18 Arrangements characterised by circuits or components specially adapted for receiving
• CPC Class Codes: H04H 60/11 Arrangements for counter-measures when a portion of broadcast information is unavailable

Abstract

A digital broadcast receiving apparatus, which has a receiving circuit for receiving a transmitted high frequency signal of a plurality of time division multiplexed programs, includes a circuit for selecting a better receiving characteristic condition while a desired program is not received.

Claims

1. A digital broadcasting receiving apparatus, having a receiving circuit for receiving a transmitted high frequency selected program signal of a plurality of time division multiplexed programs, comprising:

an electric field strength detector for detecting the strength of an electric field;

an error ratio measuring circuit for measuring errors in received data packets;

a radio frequency variable gain circuit having a radio frequency operation starting point, the radio frequency operation starting point determining a radio frequency power level of the radio frequency variable gain circuit;

a baseband variable gain circuit having a baseband operation starting point, the baseband operation starting point determining a baseband power level of the baseband variable gain circuit;

an operation starting point controlling circuit that varies;

a) the radio frequency operation starting point to start operation from a low radio frequency power level which is lower than a high radio frequency power level used when detecting the electric field strength and measuring the errors, and

b) the baseband operation starting point to start operation from a high baseband power level which is higher than a low baseband power level used when detecting the electric field strength and measuring the errors,

wherein while receiving the plurality of time division multiplexed programs other than the selected program, the radio frequency operation starting point and the baseband operation starting point are varied in accordance with a) and b) in response to the detected electrical field strength being above a predetermined electric field threshold and the measured errors in the received data packets being above a predetermined error threshold.

2. The digital broadcasting receiving apparatus according to claim 1, wherein a parameter switch timing generating circuit controls a switch in response to the detected electrical field strength, wherein the switch switches between a vertically polarized antenna and a horizontally polarized antenna.

3. The digital broadcasting receiving apparatus according to claim 1, including an analog to digital converter, an output signal of the baseband variable gain circuit is an input signal to the analog to digital converter,

wherein the radio frequency operation starting point and the baseband operation starting point are varied to ensure that the input signal to the analog to digital converter maintains a constant level.