Synaccess Networks NP-0801DTM - Manual (Page 316)

AUDIO COMMANDS
HSPA+ AT Commands Reference Guide 316
Parameters and Values
<char>
<aFn>,<bFn>,<aSn>,<bSn> ‐ they all are specific parameters for the calculation of
digital biquad filters as follows:
2
2
1
1
2
2
1
1 0
2 1
2
) (
− −
− −
⋅ + ⋅ ⋅ +
⋅ + ⋅ ⋅ +
=
z b z b
z a z a a
z H
F F
F F F
F
2
2
1
1
2
2
1
1 0
2 1
2
) (
− −
− −
⋅ + ⋅ ⋅ +
⋅ + ⋅ ⋅ +
=
z b z b
z a z a a
z H
S S
S S S
S
‐32768‐32767 ‐ each value has to be interpreted as signed fixed point number in
two’s complement format with 15 fractional bits in a 16 bit word (Q15)
Note: In the above formulas pay attention to the multiplier (2) for parameters
<aF1>, <aS1>, <bF1> and <bS1>
Parameters can be saved in non‐volatile memory using AT#PSAV command and
are available for audio profiles 1,2,3. For audio profile 0 the values are fixed.
Cascaded Filters #BIQUADOUT
Set command allows to configure the parameters of the two cascaded digital biquad filters
) ( ) ( z H z H
Second First
⋅
in Downlink path (receiving). It is not allowed if active audio profile is 0.
Read command returns the parameters for the active profile in the format:
# BIQUADOUT: <aF0>,<aF1>,<aF2>,<bF1>,<bF2>,<aS0>,<aS1>,<S2>,<bS1>,<bS2>
It is not allowed if active audio profile is 0.
Test command returns the supported range of values for <aF0>, <aF1>, <aF2>, <bF1>, <bF2>, <aS0>, <aS1>, <aS2>,
<bS1>, <bS2>
Syntax
Command Command type
AT#BIQUADOUT=<aF0>[,<aF1>[,<aF2>[,<bF1>[,<bF2>[,<aS0>[,<aS1>[,<aS2>
[,<bS1>[,<bS2>]]]]]]]]] Set
AT#BIQUADOUT? Read
AT#BIQUADOUT=? Test