Re: taps for a Raised Cosine function

A raised cosine is also known as a Hann window. https://www.gnuradio.org/doc/doxygen/classgr_1_1fft_1_1window.html#a599d7e9625d6cc77203a8b877c4911e2a0099ec5d7a2ab5d7a7f3fd7f7835c72a Example usage:

Re: Reliable "virtual RF channel" between two grc applications (UDP Source/Sink?)

On Wed, Apr 22, 2020 at 10:48 AM Lukas Haase wrote: > > Has anyone done something like this before and has a recommendation for a > reliable setup? > Is UDP Source/Sink over localhost even the best way to go? > If you just want to connect two local processes, you could try using mkfifo

Compensating for sample delay in one audio source channel

I have an audio interface (behringer UCA222) which, for whatever reason, has a 1 sample delay in one of the input channels. Consequently, the two input channels have unequal phase across the entire bandwidth. I'd like to compensate for that. I measured the delay with this flow graph: [image:

Re: [Discuss-gnuradio] Moving average

from __future__ import division ...in the script at the top or as a GRC block will also do the trick. On Tue, Jan 22, 2019, 17:42 Cinaed Simson On 1/22/19 4:59 AM, david vanhorn wrote: > > Nope. > > > > 1/Averaging evaluates to zero. > > 1/Averaging. (trailing period) does not evaluate, either

Re: [Discuss-gnuradio] [Freetel-codec2] Why the DMR 4FSK modem is less optimal than David Rowe's 4FSK modem

Wouldn't the ISI largely (theoretically, completely) be ameliorated by trellis decoding? And I'm not talking about FEC, but rather incorporating the ISI into the expected Cartesian coordinates for each symbol. I did some experimentation with this technique on BPSK31, and I was able to get a

Re: [Discuss-gnuradio] Good SNR despite rotating constellation

On Tue, Jul 4, 2017 at 6:30 AM Rafik ZITOUNI wrote: > Could you give me an explanation how it was possible to obtain a good snr > and ber with a wrong constellation with good SNR and BER? > for BPSK the value of the bit is determined only by examining the sign of the real

Re: [Discuss-gnuradio] FM Modulation problem/question

On Mon, Jun 26, 2017 at 1:50 PM Brashendeavours wrote: > Thank you, Kevin. That is reassuring. > > My next question then, is since the deviation is affected by both > amplitude and frequency, how would you recommend I empirically > determine/set a peak deviation of

[Discuss-gnuradio] AGC for PAM

I'm working on a BPSK demodulator, which I guess is a kind of PAM. The signal has some inherent ISI so I'm using Viterbi to decode it. It's working well in idealized conditions, but I'm a bit lost on how to get the amplitude right. It seems important that the amplitude is consistent (modulo noise)

Re: [Discuss-gnuradio] Clock recovery for BPSK with intentional ISI

be difficult, so this may be worth trying. > best > Federico > > 2017-06-15 9:57 GMT-03:00 Phil Frost <ind...@bitglue.com>: > >> I am working on a receiver for the amateur radio mode PSK31[1]. It's BPSK >> where the pulses are a raised cosine (impulse, not freque

[Discuss-gnuradio] Clock recovery for BPSK with intentional ISI

I am working on a receiver for the amateur radio mode PSK31[1]. It's BPSK where the pulses are a raised cosine (impulse, not frequency domain) twice the symbol duration[2], no error correction, at 31.25 baud. The transmitted signal has no ISI, but after matched filtering it does: [image:

[Discuss-gnuradio] Audio latency keeps increasing

I'm prototyping some software which uses a PulseAudio sink/source pair which I wrote[1]. Even doing something as simple as having the audio source go into a GUI sink and the audio sink, I'm having an issue where as the program runs longer, the latency gets higher. Running for a day the latency

[Discuss-gnuradio] Synchronization in FreeDV (PSK FDM)

I'm trying to demodulate FreeDV as a learning exercise. Without much experience in DSP I'm afraid I'm lost in the source code :( The modulation consists of 15 subcarriers each with a symbol rate of 50 per second, spaced 75 Hz apart. The center subcarrier is BPSK and alternates phase every symbol

Re: [Discuss-gnuradio] new to GNUradio: AFSK and codec2 gmsk modem

On 07/30/2013 08:51 PM, Gregory Warnes wrote: How about enclosing the bit-for-bit tests in #ifdef IEEE754_Compliant ... #endif Merely knowing that a platform conforms to IEEE 754 is not sufficient to guarantee bit-for-bit compatibility. The order of operations also matters, and compliers

[Discuss-gnuradio] Adjusting IQ balance for audio sources

I'm wondering what block GnuRadio offers to adjust IQ balance to maximize image rejection from an audio source. Is there a block available, or a description of a (perhaps manual) algorithm I can implement with existing blocks? ___ Discuss-gnuradio

Re: [Discuss-gnuradio] Announcing new scheduler for GNU Radio

On 04/17/2013 09:45 AM, Philip Balister wrote: On 04/17/2013 04:26 AM, Josh Blum wrote: Behind all of the GRAS fluff, the Theron C++ concurrency library is the real scheduler. I dislike projects that force you to enter an email address to download the source and do not provide access to the

Re: [Discuss-gnuradio] Voice over IP using GNu Radio.

On 03/03/2013 06:18 AM, Sajjad Safdar wrote: Is there any way of transmitting voice over ip using GNu Radio Companion. To the extent that you can define what networking, modulation, and VoIP protocols you intend to use, yes. ___ Discuss-gnuradio