Unlock instant, AI-driven research and patent intelligence for your innovation.

Processor for an FM signal receiver and processing method

A signal and difference signal technology, applied in broadcast receiving circuits, stereo broadcast reception, broadcast information features, etc., can solve problems such as FM signal deterioration

Active Publication Date: 2013-07-31
NXP BV
View PDF10 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0011] Noise causes FM signal degradation when FM tuner reception quality deteriorates
However, the sum and difference signals are affected differently

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Processor for an FM signal receiver and processing method
  • Processor for an FM signal receiver and processing method
  • Processor for an FM signal receiver and processing method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0044] The invention provides a processing unit for processing multi-channel audio signals, in which processing unit frequency-based noise suppression is applied to the difference signal. This denoising may be combined with an adaptive gain factor based at least on the magnitude of the noise signal in the frequency domain. The noise suppression gain function is limited to maximum and minimum values ​​to reduce distortion caused by noise suppression.

[0045] image 3 A flowchart of the invention is shown, in which optional components are indicated by dashed lines. The process starts with three time-domain signals: sum, diff and diffnoise (the output of the FM tuner, see figure 1 )start.

[0046] In step 30 the diff and diffnoise signals are transformed into the frequency domain. In step 31 a gain function is calculated from the signal amplitude and in step 32 the gain function is limited to maximum and minimum values. In step 33 a gain function is applied to the frequency d...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A processing unit for processing a multi-channel audio signal has a delay element (40) for delaying an FM sum signal (sum) and a converter arrangement (T) for converting an FM difference signal (diff) and a noise signal (diffnoise) to the frequency domain. Frequency-based noise suppression is used to derive a de-noised frequency-domain difference signal using a gain function which is limited to a maximal and a minimal value. This is then converted to the time domain, and the first and second audio signals are calculated from a delayed sum signal (sum2) and the de-noised time domain difference signal (diff2).

Description

technical field [0001] The invention relates to an FM signal receiver and a receiving method. Background technique [0002] In FM broadcasting, the demodulated FM stereo signal consists of: a monotone signal in the form of a sum signal (L+R, "main" channel) transmitted as baseband audio in the range 30Hz to 15kHz; a pilot tone at 19kHz; and A stereo difference signal (L-R, "sub" channel) amplitude modulated on a 38kHz subcarrier occupying the 24kHz to 53kHz range. [0003] Representing stereo audio signals as sum and difference signals instead of left and right audio signals ensures compatibility with monophonic receivers that use only the main channel. [0004] figure 1 is a schematic diagram of an FM tuner that converts FM radio broadcasts to audio signals. The tuner produces three output signals from a given FM broadcast: a sum signal ("sum"), a difference signal ("diff") and a signal representing the noise present in the difference signal ("diffnoise"). A diffnoise s...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): H04B1/16
CPCH04H20/89H04B1/1676H04H40/72
Inventor 泰穆金·高塔马
Owner NXP BV