SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R26
System description
Page 74 of 217
I2S_RXD
UBF
2/6
UBF
1/5
Hands-
free
To
Radio TX
Scal_Mic
Digital Gain
I2S_TXD
Scal_Rec
Digital Gain
Tone
Generator
UBF
4/8
UBF
3/7
DBF
3/7
DBF
4/8
DBF
1/5
DBF
2/6
Legend:
UBF= Uplink Biquad Filter
DBF = Downlink Biquad Filter
NR = Noise Reduction
Sidetone
From
Radio RX
Speech level
UPLAYFILE
Mix_Afe
URECFILE
UAPLAY
UAREC
UPLAYFILE
URECFILE
Mix_Afe
UAPLAY
UAREC
NR
Figure 34: SARA-U2 “04” product versions audio processing system block diagram
For a detailed description about audio parameter tuning, see the
SARA-U2 series extended audio processing
blocks commands application note
SARA-U2 modules audio signal processing algorithms are:
Speech encoding (uplink) and decoding (downlink).The following speech codecs are supported in firmware
on the DSP for speech encoding and decoding:
GERAN GMSK codecs
o
GSM HR (GSM Half Rate)
o
GSM FR (GSM Full Rate)
o
GSM EFR (GSM Enhanced Full Rate)
o
HR AMR (GSM Half Rate Adaptive Multi Rate – Narrow Band)
o
FR AMR (GSM Full Rate Adaptive Multi Rate – Narrow Band)
o
FR AMR-WB (GSM Full Rate Adaptive Multi Rate – Wide Band)
UTRAN codecs:
o
UMTS AMR2 (UMTS Adaptive Multi Rate version 2 – Narrow Band)
o
UMTS AMR-WB (UMTS Adaptive Multi Rate – Wide Band)
Mandatory sub-functions:
o
Discontinuous transmission, DTX (GSM 46.031, 46.041, 46.081 and 46.093 standards)
o
Voice activity detection, VAD (GSM 46.032, 46.042, 46.082 and 46.094 standards)
o
Background noise calculation (GSM 46.012, 46.022, 46.062 and 46.092 standards)