## Forums comp.dsp

## Need resources to implement WIFI on USRP devices.

Hi, Iam Eshwar. I realized 16qam,DSSS, FH based radios on USRP.Now i want to implement complete wifi on usrp. I need some resources on...

Hi, Iam Eshwar. I realized 16qam,DSSS, FH based radios on USRP.Now i want to implement complete wifi on usrp. I need some resources on standards (frame formats,modulation schemes,channel coding ..etc). I went through 802.11g standards.Iam confused on where to start with. Requirement : I will use USRP with laptop_1(connected to internet) on oneside and other side i will use...

## Matlab code needed for SSB demodulation

inHi Guys, I'm trying to help someone understand the operation of a discrete single-sideband (SSB) demodulation system that is being...

Hi Guys, I'm trying to help someone understand the operation of a discrete single-sideband (SSB) demodulation system that is being proposed to replace an older analog SSB demodulation system. Having not thought about SSB systems for many years, I've been trying to figure out how the "phasing method" of SSB demodulation works. In trying to model this "phasing method" using Matla...

## Good references on ultrasound beamforming and imaging

inHi everyone I hope this is the right group since I'm interested in the signal processing aspect mote than the physics itself. I'm trying to...

Hi everyone I hope this is the right group since I'm interested in the signal processing aspect mote than the physics itself. I'm trying to look for good references (either books or papers) that go over some ultrasound imaging and beamforming algorithms. Basically, things like delay and sum, dynamic focusing, adaptive beamforming, etc. Hopefully, it would also include ultrasound ima

## Generalized Cross Product

inI have a pair of N-dimensional vectors, N large (hundreds), and I need to generate another N-dimensional vector that is orthogonal to the first...

I have a pair of N-dimensional vectors, N large (hundreds), and I need to generate another N-dimensional vector that is orthogonal to the first two. It doesn't have to be unique; it doesn't even have to be perfectly orthogonal, as long as the normalized dot products are less than, oh, about 0.005. I've searched for "generalized cross product" and similar terms, and all I found was a

## Shannon and Sphere Hardening

inSo, I'm toying with Shannon's capacity theorem, trying to graph out the "sphere hardening" effect that he cites as the basis of the...

So, I'm toying with Shannon's capacity theorem, trying to graph out the "sphere hardening" effect that he cites as the basis of the principle. I can see, intuitively, how the whole notion that the volume of a sphere is concentrated in a thin shell works, but when I try to calculate actual numbers I start running into numerical difficulties at dimensions of around 150 or 200. Even wit...

## OT: Flash Memory

inGentle comp.dsp People, I've been involved on several projects over the past few years that utilize flash memory in microSD form, and several...

Gentle comp.dsp People, I've been involved on several projects over the past few years that utilize flash memory in microSD form, and several times they have inquired about problems with lifetime of such cards. My employer recently tasked me with investigating the alleged write lifetime issue. Frankly I was appalled at the numerous, significant issues I found in current-day cards. Doe...

## Constitutional encoding/ decoding

inHaving a hard time figuring out how to properly do soft decoding with vitdec for bpsk. I tried using 'unquant' but my results are the same as hard...

Having a hard time figuring out how to properly do soft decoding with vitdec for bpsk. I tried using 'unquant' but my results are the same as hard decision decoding. trellis = poly2trellis(4,[11 15]); for i = 1:7 for q = 1:n_block %create coded message code = convenc(msg(:,q),trellis); %convert to bpsk code_bpsk = 2*code-1; %add noise tx = code_bpsk' + sqrt(No(i)/2)*...

## OT: AEC

inI am working on a project and looking to license a commercial-grade software AEC. How much should I expect to pay to license a SW AEC and how much...

I am working on a project and looking to license a commercial-grade software AEC. How much should I expect to pay to license a SW AEC and how much in royalty per unit. I expect that it will be used in 10000 units the first year. Thanks.

## Overlapping sub bands in WOLA channelizer

inHi, I would like to create a WOLA channelizer with overlapping passbands, say 25%, but I'm struggling to see how I could do this as my...

Hi, I would like to create a WOLA channelizer with overlapping passbands, say 25%, but I'm struggling to see how I could do this as my math isn't up to it. I can imagine having two channelizers operating on overlapping input samples and then interleaving the output from the channelizers to increase the sample rate but I'm pretty sure this doesn't get me much closer. Anyone been down this r...

## Why is Dolph-Chebychev windowing relatively obscure?

inMost software seems to focus on Hann, Hamming, and Blackman windowing. From the graphs I've seen, Dolph-Chebychev appears to outperform...

Most software seems to focus on Hann, Hamming, and Blackman windowing. From the graphs I've seen, Dolph-Chebychev appears to outperform them: https://en.wikipedia.org/wiki/Window_function#Dolph.E2.80.93Chebyshev_window Anyone know why it isn't featured in DSP texts to the extent of the other windows above? Are there drawbacks?

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