×

Encoding and decoding of a wideband digital information signal

  • US 5,661,755 A
  • Filed: 10/20/1995
  • Issued: 08/26/1997
  • Est. Priority Date: 11/04/1994
  • Status: Expired due to Term
First Claim
Patent Images

1. An apparatus for encoding a wideband digital information signal, the apparatus comprising:

  • an input for receiving the wideband digital information signal,signal splitting means for, during a specific time interval, splitting the wideband digital information signal into M narrow band sub signals, each one of the M sub signals being representative of a component of the wideband digital information signal which is present in a corresponding one of M adjacent narrow bands in the frequency band of the wideband digital information signal, where M is an integer larger than 1 and the narrow bands all have a specific constant bandwidth,scale factor determining means for determining one or more scale factors for subsequent signal blocks in each of the sub signals,quantization means for quantizing the samples in signal blocks into quantized samples in response to bit allocation information supplied to the quantizing means so as to obtain quantized sub signals,bit allocation information deriving means for deriving the bit allocation information, the bit allocation information for a signal block being representative of the number of bits with which samples in a signal block of a sub signal will be represented after quantization in the quantization means,formatting means for combining quantized samples in the signal blocks of the quantized sub signals and scale factors into a digital output signal having a format suitable for transmission or storage, andsignal block length determining means for determining the lengths of the signal blocks in at least one of the sub signals and for generating block length information, the block length information being representative of the lengths of the signal blocks in the at least one sub signal, where the lengths of subsequent signal blocks in the at least one sub signal differ,wherein the scale factor determining means is adapted to determine the scale factors for subsequent signal blocks of varying lengths in the at least one sub signal in response to the block length information, the bit allocation information deriving means is adapted to derive bit allocation information for subsequent signal blocks of varying lengths in the at least one sub signal in response to the block length information, the quantization means is adapted to quantize the samples in signal blocks of varying lengths in the at least one sub signal in response to the block length information, and the formatting means is adapted to include the block length information in the digital output signal.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×