Processing

Please wait...

Settings

Settings

Goto Application

1. WO2008041216 - A SIGMA-DELTA MODULATOR

Publication Number WO/2008/041216
Publication Date 10.04.2008
International Application No. PCT/IE2007/000092
International Filing Date 04.10.2007
IPC
H03M 7/32 2006.01
HELECTRICITY
03BASIC ELECTRONIC CIRCUITRY
MCODING, DECODING OR CODE CONVERSION, IN GENERAL
7Conversion of a code where information is represented by a given sequence or number of digits to a code where the same information is represented by a different sequence or number of digits
30Compression; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
32Conversion to or from delta modulation, i.e. one-bit differential modulation
H03M 7/36 2006.01
HELECTRICITY
03BASIC ELECTRONIC CIRCUITRY
MCODING, DECODING OR CODE CONVERSION, IN GENERAL
7Conversion of a code where information is represented by a given sequence or number of digits to a code where the same information is represented by a different sequence or number of digits
30Compression; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
36Conversion to or from differential modulation with several bits, i.e. the difference between successive samples being coded by more than one bit
CPC
H03M 7/3028
HELECTRICITY
03BASIC ELECTRONIC CIRCUITRY
MCODING; DECODING; CODE CONVERSION IN GENERAL
7Conversion of a code where information is represented by a given sequence or number of digits to a code where the same ; , similar or subset of; information is represented by a different sequence or number of digits
30Compression
3002Conversion to or from differential modulation
3004Digital delta-sigma modulation
3015Structural details of digital delta-sigma modulators
302characterised by the number of quantisers and their type and resolution
3024having one quantiser only
3028the quantiser being a single bit one
H03M 7/3042
HELECTRICITY
03BASIC ELECTRONIC CIRCUITRY
MCODING; DECODING; CODE CONVERSION IN GENERAL
7Conversion of a code where information is represented by a given sequence or number of digits to a code where the same ; , similar or subset of; information is represented by a different sequence or number of digits
30Compression
3002Conversion to or from differential modulation
3004Digital delta-sigma modulation
3015Structural details of digital delta-sigma modulators
3031characterised by the order of the loop filter, e.g. having a first order loop filter in the feedforward path
3042the modulator being of the error feedback type, i.e. having loop filter stages in the feedback path only
Applicants
  • UNIVERSITY COLLEGE CORK - NATIONAL UNIVERSITY OF IRELAND, CORK; [IE]/[IE] (AllExceptUS)
  • KENNEDY, Michael, Peter [IE]/[IE] (UsOnly)
  • HOSSEINI, Kaveh [IR]/[IE] (UsOnly)
Inventors
  • KENNEDY, Michael, Peter
  • HOSSEINI, Kaveh
Agents
  • O'BRIEN, John, A.
Priority Data
2006/072504.10.2006IE
Publication Language English (EN)
Filing Language English (EN)
Designated States
Title
(EN) A SIGMA-DELTA MODULATOR
(FR) MODULATEUR SIGMA-DELTA
Abstract
(EN)
A digital to digital Sigma-Delta modulator (100) of order L comprises a signal input (10, 110, 210) to receive a digital input value encoded over a given number no of bits, where no is an integer; and an output (20, 120, 220) for delivering a digital output value encoded over a given number m of bits, where m is an integer less than no. There is at least one Sigma-Delta cell comprising an adder (A1, A11, A21) for receiving an input signal and feedback, and a quantizer (Q1, Q11, Q21) with interval M. The cell further comprises a gain component (DG1, G22) for monitoring the quantizer and for adding a number w to the state of the cell. The number w is added according to the output of the quantizer in order to offset the cell state so that the cell sequence length (M-w) L becomes a power of a prime number. Preferably, the quantizer (Q1, Qi 1, Q21) interval M satisfies M = 2 No. The effect of the auxiliary feedback is to spread the energy over a large number of tones, independently of the input and initial conditions, as illustrated in Fig. 4 (b).
(FR)
L'invention concerne un modulateur (100) Sigma-Delta numérique à numérique d'ordre L, qui comporte une entrée de signal (10, 110, 210) pour recevoir une valeur d'entrée numérique codée sur un nombre donné no de bits, où no est un entier ; et une sortie (20, 120, 220) pour produire une valeur de sortie numérique codée sur un nombre donné m de bits, où m est un entier inférieur à no. Il existe au moins une cellule Sigma-Delta comportant un additionneur (A1, A11, A21) pour recevoir un signal d'entrée et une rétroaction, et un quantificateur (Q1, Q11, Q21) avec un intervalle M. La cellule comporte en outre un composant de gain (DG1, G22) pour surveiller le quantificateur et pour ajouter un nombre w à l'état de la cellule. Le nombre w est ajouté conformément à la sortie du quantificateur afin de décaler l'état de cellule, de telle sorte que la longueur de séquence de cellule (M-w) L devient la puissance d'un nombre premier. De préférence, l'intervalle de quantificateur (Q1, Q11, Q21) M satisfait M = 2 No. L'effet de la rétroaction auxiliaire est d'étaler l'énergie sur un nombre important de sons, indépendamment de l'entrée et des conditions initiales, tel qu'illustré par la Figure 4 (b).
Latest bibliographic data on file with the International Bureau