Specifications

AirPrime UMTS / LTE MC/SL-Series Extended AT Command Reference
128 Proprietary and Confidential 2130616
The modems also provide 13-tap FIR (Finite Impulse Response) filtering for both
the receive and transmit paths to equalize the acoustic response of the speaker
and microphone.
The embedded module can serve as an integral component of a more complex
audio system, such as a PDA with a separate codec interfacing with the main
processor. In this case, the interface between the modem and PDA codec can be
as simple as line-level audio with no transducer considerations. Phone-oriented
functions such as echo cancellation and FIR filtering are typically left to the
module, while path-switching and transducer interfaces are the responsibility of
the PDA codec. Functions such as adjustable gain and volume settings, DTMF
and ringer tone generation, and mixing can be accomplished in either codec,
depending on the architecture of the particular product. The interface between the
module and host audio systems is usually the primary audio interface set to line-
level amplitudes, routed as differential pairs for noise immunity.
Figure 7-1: Mini Card audio block diagram
Audio profiles
The AT command set allows you to have different audio configurations for
different purposes. As an example, assume you are embedding the module in a
device that has a handset mode and a speakerphone mode. Assume also that
you want to use different transmit gain, noise suppression, and echo cancellation
settings in each mode. You can store the settings for each mode in separate
audio profiles, then activate the appropriate profile as your application switches to
handset or speakerphone mode.
The AirPrime UMTS/LTE embedded module supports some combination of the
following audio profiles, depending on the module type:
• 0—Handset (MSM6290, QSC6270)
• 1—Headset (MSM6290, QSC6270)