help on abs() within matlab Hi, I'm new to matlab and I'm developing fft matlab code for hardware prototype. I have passed floating point code and try to verify it with fixed point algorithm. I met problem here. 1). I use fi(x) to define input and then use fft(x) to check matlab original results. I got message: Function 'fft' is not defined ... 10 Jun 2010 04:31 Q1.15 calculation 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... 19 Jun 2010 08:00 Kenlighten - A social network for knowledge seekers and providers Dear friends, I am writing to share with you about a unique social knowledge network - Kenlighten http://www.kenlighten.com . At Kenlighten you can register for a free account and create online tutorials in your area of expertise by uploading your ebooks, presentations, articles, videos, audio files. You can a... 8 Jun 2010 01:28 audio DSP SIG in Seattle 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. ... 8 Jun 2010 01:28 inverse z-transform - partial fractions [IMG]http://i50.tinypic.com/28sbn6f.png[/IMG] ... 9 Jun 2010 10:49 implementing MUSIC/Pisarenko algorithm in Matlab Hi guys, I am trying to implement the MUSIC algorithm and the more specialized case of Pisarenko and I am not sure if my approach is a good one. I am following the algorithm from the book "Spectral analysis of signals" by Moses and Stoica and the way I figured it out that it would work is by: - having a method th... 7 Jun 2010 17:42 Converting IIR filter to different sample rates 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, ... 10 Jun 2010 14:31 please DSP simple FPGA example Hi I was wondering if anyone would provide me with a simple example on how to implement a low pass filter using a FPGA Just need something to get me started. I understand DSP and know some HDL but can't figure out how to implement LPF... ... 7 Jun 2010 10:44 Bidirectional equalization Hello, I'm simulating a Decision Feedback Equalizer for MSK signal, using the well know LMS algorithm. In order to get better performance I tried to equalize each packet in two stages. The structure of the packet is as follows: [Payload1 TrainingSeq Payload2] Since the training sequence is placed in the middle (G... 15 Jun 2010 16:30 delay diversity Hello all. There is an early type of space-time codes called 'delay diversity'. To refresh your memory, y(t) = h0 x x1. y(t+T) = h0 * x2 + h1 * x1 y(t+2T) = h0 * x3 + h1 * x2 This is of course equivalent to a frequency selective transmission of two symbols. Here is what I don't understand. 1) In the te... 5 Jun 2010 12:29