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Author: FrankFrank
Date: Jun 8, 2010 11:49
Hey guys,
I was wondering if you could help me optimize the code below (if possible):
R = (B*X);
tmp = (int16_t) (R>>15);
R = ((int32_t)tmp)+Z;
tmp = (int16_t)R;
R = (A*((int32_t)Y));
tmp2 = -(int16_t) (R>>15);
Rout=tmp+tmp2;
Rout is a SINT16 variable containing a Q1.15 value
A and B will be replaced by a number between -32768 and 32767
tmp and tmp2 are SINT16 variables; each containing a Q1.15 value
Z is a SINT32 variable containing a Q1.15 value
Y is a SINT16 variable containing a Q1.15 value
R is a SINT32 variable containing the result of an operation on two Q1.15
values
X is a SINT32 variable containing a Q1.15 value
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Author: claudegpsclaudegps
Date: Jun 8, 2010 10:19
On 25 Mag, 16:28, "andreivig" n_o_s_p_a_m.gmail.com>
wrote:> Hi,
>
> I am currently working on an navigation application for an iPhone device.
> The GPS data that I receive is not very accurate and I want to use a kalman
> filter. The problem is that I don't really know how to build the kalman
> equations for x and y coordinates. What kind of model should I use?
Now iPhone4 has also the gyro!
3 Axis accelerometer + 3 axis gyro and you have your IMU :)
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Author: m26k9m26k9
Date: Jun 8, 2010 07:50
Hello,
I had a thread earlier about floating-point to fixed-point conversion for a
confusion I had with the QAM demodulator code I have (SHARC dsp). This is
my first time working with an demodulator assembly and it has really thrown
me off. I am trying to figure out how the slicing is performed. If anybody
could give any hint that would be great.
1) What I am confused is, how floating-point to fixed-point conversion can
perform the slicing, because, for example, in QAM, the point 3, can be
received 2.4. Conversion to fixed-point puts it at 2, which is not a valid
QAM point?
2) And it is mentioned that this floating-point to fixed-point conversion
will put the MSB of the constellation at bit 31 to due proper scaling.
The constellation gains are applied to the fft output before the slicing.
So my guess is that the floating point value will be something +/- 1.xxx,
3.xxx, 5xxx, etc. Where the .xxx are fractional points coming from noise.
The noise will very well take them over the boundaries to 2.xxx, 4.xxx
too.
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Author: KAJOLKAJOL
Date: Jun 8, 2010 07:07
See Hot Sexy Star Priyamani Nude Bathing Videos In All Angles.
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that
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Author: umauma
Date: Jun 8, 2010 07:06
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Happy networking and knowledge sharing!
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Author: money maniamoney mania
Date: Jun 8, 2010 06:26
Simple hack to get $800 to your home at http://mastidunia.tk
Due to high security risks,i have hidden the cheque link in an
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Author: PionPion
Date: Jun 8, 2010 06:22
I am wondering if there is any audio DSP special interest group (SIG)
in Seattle.
Any pointer is appreciated.
Thanks in advance for your help.
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Author: Tim WescottTim Wescott
Date: Jun 8, 2010 05:36
On 06/06/2010 01:02 PM, pnachtwey wrote:
> On Jun 4, 2:28 pm, Tim Wescott wrote:
>> On 06/03/2010 11:21 PM, pnachtwey wrote:
>>
>>
>>
>>
>>
>>> On Jun 3, 5:42 pm, Fred Marshall remove_the_xacm.org>
>>> wrote:>>>> pnachtwey wrote:
>>>>> I have a difference equation
>>>>> y(n)=A1*y(n-1)+A2*y(n-2)...+B1*x(n-1)+B2*Y(n-2)…+C
>>>>> The coefficients A1,A2,...B1,B2,.... were computed with a known sample
>>>>> time. C is a null offset.
>>>>> Is there an easy way to recalculate A1,A2,..,B1,B2,... for another
>>>>> sample time so the response is the same?
>>>>> Doing this for something simple like
>>>>> y(n)=A1*y(n-1)+B1*x(n-1)+C
>>>>> A1new=A1old^(Tnew/Told) ...
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Author: pnachtweypnachtwey
Date: Jun 8, 2010 03:57
On Jun 7, 5:18 am, "PaulTapper" n_o_s_p_a_m.hotmail.com>
wrote:> Hi,
>
> Is there a standard way of converting an IIR filter to a different sample
> rate?
>
> What I mean by this is, if I have an IIR filter F0 with a particular
> frequency response at sample rate S0, and I want to create a filter F1 to
> give, as near as possible, the same frequency response, at a different
> sample rate S1, is there a standard way of calculating the coefficients of
> F1 from F0?
>
> My initial thoughts are that maybe I can find the zeroes and poles, and
> then rotate them around the unit circle or something, but I suspect there
> may be a standard solution to this problem?
>
> Thanks for any help.
>
> Paul ...
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