7 Computational details and bit allocation

06.923GPPComfort noise aspects for Adaptive Multi-Rate speech traffic channelsTS

A bit exact computational description of comfort noise encoding and generation in form of an ANSI-C source code is found in GSM 06.73 [2].

The detailed bit allocation and the sequence of bits in the comfort noise encoding is shown in table 1.

Table 1: Source encoder output parameters in order of occurrence
and bit allocation for comfort noise encoding

Bits (MSB‑LSB)

Description

s1 – s3

index of reference vector

s4 ‑ s11

index of 1st LSF subvector

s12 – s20

index of 2nd LSF subvector

s21 – s29

index of 3rd LSF subvector

s30 – s35

index of logarithmic frame energy

Annex A (informative):
Document change history

SMG#

SPEC

CR

PHASE

VERS

NEW_VERS

SUBJECT

29

06.92

A001

R98

7.0.0

7.1.0

Correction of averaging formula

06.92

7.1.0

7.1.1

Update to Version 7.1.1 for Publication