Questions tagged [qpsk]

Quadrature Phase Shift Keying

Filter by
Sorted by
Tagged with
0
votes
1answer
273 views

dvb-s to dvb-c direct transmodulation

Is this possible to direct trans modulate DVB-S/S2 -> QI into -> DVB-C/C2 signals without doing it the way DVB-S/S2->Demodulator.ic-Transport Stream -> Modulator.ic-Transport Stream -> DVB-C/C2 ? Qpsk ...
0
votes
0answers
21 views

Questionable Eb/N0 results for different modulations - measurements for 8-PSK do not match the theory

I would like to warn you that this post will be long, so thank you in advance to everyone who reads it and is able to help. I am running a certain simulation. I created a measurement environment (...
0
votes
0answers
5 views

Simulating Rayleigh channel - Problem with adding channel coefficents

I am currently trying to simulate a Rayleigh channel using python (numpy). Full Jupyter Notebook on GitHub: Jupyter Notebook I assume that the channel changes with each new symbol. So I create myself ...
0
votes
1answer
31 views

Transferring data over sound with QAM / QPSK

Been working on a FSK Modem in the last few weeks and have gotten it to work with 400bps, very reliable, atleast over a virtual audio cable, but it also works when playing a sound directly into a ...
0
votes
0answers
48 views

QPSK transmission simulation

I am trying to simulate a QPSK transmission using GNU Radio following mpsk_stage6.grc example in Gnuradio tutorials. Currently I have no idea where is the problem and everytime I execute the flow ...
0
votes
0answers
32 views

Packet Encoder GNU QPSK Transmission

Hello everyone!. This is a template to QPSK transmission but Packet Encoder block is no longer available in new GNURadio versions, what do I need to replace this block in order to do a QPSK ...
0
votes
1answer
42 views

How to Tx CDMA signal physically using an existing point-to-point modem? [closed]

I am working in acoustic communication, I want to test CDMA network capabilities in acoustic environment. I had an acoustic modem that has serial interface, a WHOI micromodem. How can i serialized ...
0
votes
0answers
19 views

What is the QPSK Constellation Diagram used in LTE

I think the question is pretty straightforward. I have to do a class project that requires me to modulate a signal, and one of the steps is Quadrature Phase Shift Keying (QPSK). It is to be done in ...
0
votes
0answers
30 views

QPSK matlab/simulink Quantisation effects

I am trying to simulate the effects of quantization of an ADC on different waveforms (e.g. QPSK,8PSK) in Simulink. For the case of QPSK the default BER curve would be generated with 2 bits per symbol ...
0
votes
1answer
63 views

Digital Tanlock carrier recovery loop

I’m currently trying to understand a digital tanlock carrier recovery loop for QPSK (for example) I cannot understand how it works. For example we an ideal QPSK constellation. phi = atan2(Q/I) = pi/...
0
votes
0answers
70 views

Nyquist sampling theorem / Nyquist - Shannon theorem evaluation over M-PSK

I am trying to simulate an M-PSK Tx-Rx System on Simulink and analyse what the effect of sampling rate reduction would have on it. More, particular I am trying to prove what Nyquist sampling theorem ...
0
votes
0answers
33 views

Learning PSK Modulation and Demodulation - Good Text to Read?

Title sums it up. I am curious to see what you all suggest. I'm a newbie and just need some beginner/intermediate material. Thanks!
0
votes
1answer
55 views

Mapping soft symbols in DQPSK

I'm trying to soft decode DQPSK. According to this paper the bits are: $b_1 = \mathrm{Re}\{s_n s^*_{n-1}\}, b_2 = \mathrm{Im}\{s_n s^*_{n-1}\}$ If I put 0.707 as a 100% probability of 0: $\begin{...
0
votes
0answers
36 views

lte matlab baseband IQ recovery

I am a beginner again to signal processing, I did my degree over ten years ago, and I am relearning all my signal processing stuff. I am a software developer by trade but now I am looking at some LTE ...
0
votes
1answer
29 views

BER performance of a space-time code over Rayleigh channel model

For a given space-time code, and in general terms, how would one proceed in the evaluation of the BER performance of this code ? In order to be more clear, say i have 16 code matrices(who's elements ...
0
votes
0answers
25 views

How to compare two 802.15.4 O-QPSK modulated digitals signals?

I am working on wireless sensors project and I am trying to simulate a transmission between two nodes. So let's say I have two nodes which transmit the message to each other, i.e. node 1 transmits ...
0
votes
0answers
60 views

what waveform using to send qpsk signal with IQ tranceiver

I have an SDR tranceiver (AD9361 on fmcomms3) working with IQ channels, i wanted to make a c++ software that modulate and send a digital QPSK signal but i'm a beginner in digital signal processing and ...
0
votes
0answers
619 views

Sampling rate versus number of sample of I and Q

I am acquiring data of an O-QPSK signal (chip rate : 2Mchip/s) with a SDR. I am undersampling the signal at 20 Mhz (carrier is at 2.8 GHz) so I respect the Shannon-Nyquist criterion that you need to ...
0
votes
2answers
2k views

GNU Radio QPSK 4 Symbols

I'd like to generate a simple QPSK signal in GNU radio, but so far I haven't been able to get it to perform the way I'd like and I'm not sure if this has to do with some misunderstanding I have about ...
-1
votes
1answer
1k views

The code explanation about QPSK modulation

This is the code about the QPSK modulation, and I don't understand the real part and the imaginary part code. Can anyone explain it to me if you know? Why is ...

1 2
3