Questions tagged [bpsk]

BPSK, a mechanism of modulation is expanded Binary Phase Shift Keying.

Filter by
Sorted by
Tagged with
13
votes
1answer
11k views

How to perform carrier phase recovery in software?

What are the options for recovering the phase of a BPSK signal in software? The only resources I can find online contain circuit diagrams – there seems to be no one willing to explain this to people ...
13
votes
1answer
1k views

What are the various definitions for $\rm SNR$, and their associated methods for measuring it?

The definition of $\rm SNR$ seems to be somewhat of a tower of babel in industry. What definitions of $\rm SNR$ are there (feel free to site application), and how exactly can it be measured for that ...
9
votes
2answers
4k views

How to soft decode DQPSK?

I'm successfully soft-decoding D-BPSK by taking the dot-product of the constellation-position of the symbol and of the previous symbol. If the result is >= 1, then the symbol phase hasn't changed and ...
8
votes
1answer
4k views

How to determine where to sample for demodulation of BPSK signals?

I have a simple BPSK demodulator. Very simply, the signal comes in and is split into two branches, one for I and one for Q. The I branch is mixed with a sin wave of the carrier, and the Q branch ...
7
votes
1answer
224 views

How to send / receive a short impulse in an extremely noisy signal with high timing accuracy?

I am pretty new to DSP. I need a computer to transmit data to a receiver through audio signals in a loud outdoor environment. (I am writing the software for both sender and receiver so I can design ...
6
votes
1answer
6k views

Simulating BPSK Costas Loop in Matlab

I am trying to implement BPSK demodulator in FPGA. First, I am modeling the system in MATLAB. Now, I am trying to design Costas Loop for carrier synchronization. This is the block diagram I'm trying ...
5
votes
1answer
4k views

Phase synchronization in BPSK

In BPSK for demodulation at the receiver end we do phase recovery between received wave and carrier wave. We can find the phase difference between the carrier and received waves using : PLL And ...
4
votes
4answers
6k views

Why does OFDM use cyclic-prefix while QPSK uses root-raised cosine filters?

My understanding is that BPSK/QPSK/... are often implemented with root-raised cosine (RRC) filters to reduce ISI and bandwidth. OFDM can be understood to be BPSK/QPSK/... implemented on multiple ...
4
votes
1answer
2k views

Energy per bit ($E_b$) in BPSK with non-unity channel gain

I would like to know what is exact and correct definition of $E_b$ (energy per bit) in digital communication. Consider I have a model such as r=a*x+n where <...
4
votes
1answer
766 views

Matlab: What should be the BER performance for BPSK using Constant Modulus Algorithm equalizer

I need help in plotting the Bit error curve or the symbol error curve for BPSK modulation scheme for varying Signal to Noise ratios or Eb/N0. The plot should show the simulated versus the theoretical ...
3
votes
1answer
316 views

Applying Viterbi algorithm to compensate for ISI in PSK31

I am implementing a receiver for the amateur radio mode PSK31. It is effectively a BPSK modulation with a pulse shape of a raised cosine twice the width of one symbol. Here are four consecutive pulses,...
3
votes
0answers
150 views

Synchronization of BPSK with variable-length symbols (ISO 14443)

Does anyone have an idea how one would perform BPSK symbol synchronization if symbol length is allowed to vary? As dumb as that sounds, this is not a theretical question.The "Proximity" Type B NFC ...
2
votes
2answers
1k views

Bandpass filter BPSK

I have a question concerning BPSK and the bandpass filter that seems to be sometimes placed before the receiver circuit (the receiver is a mixer and lowpass filter). Basically, from what I've noticed,...
2
votes
2answers
533 views

Prevent negative image with BPSK modulation in a complex signal

In a baseband complex signal, I need to generate a BSPK modulated signal at a given frequency. If I generate a CW at this frequency, all is good. However, when I then BPSK modulate the CW, I get a ...
2
votes
2answers
11k views

Relation between Bandwidth and Baud-Rate for 8-PSK

I have a query on relationship between Baud Rate and Bandwidth for 8-PSK. In 8-PSK as 3 bits together form a symbol, so Bandwidth = 2R/3 , R is Bit Rate As bit ...
2
votes
2answers
834 views

Why does FEC seem to make BER worse at low Eb/N0?

I've been plotting BER curves and am wondering why FEC seems to make a BER curve worse at low Eb/N0 than the un-coded theoretical BER curve? My example plot below is for Differential BPSK using a ...
2
votes
2answers
2k views

High modulation index PSK - carrier recovery

How to recover the carrier of a PSK signal that has high modulation index (eg. 750 symbols per second at carrier frequency 1500 Hz)? I guess that a PLL will not be able to lock onto it with such ...
2
votes
3answers
1k views

Real-time BPSK demodulation

I am currently studying BPSK demodulation. Most probably my question very basic but i am having difficulties to understand the case of real-time bpsk demodulation. Basically, all the examples (matlab,...
2
votes
1answer
1k views

Find beginning of signal for BPSK Demodulation

I want to store a small amount of data in a sound file recorded by a microphone but I know nearly nothing about signal processing. I managed to demodulate my data encoded using binary phase shift ...
2
votes
1answer
4k views

What is the meaning of BPSK(n)

I am doing some research into GNSS (Global Navigation Satellite Systems) and have come across various signals listed as having the in-phase or quadrature channels modulated with BPSK(2) or BPSK(10), ...
2
votes
1answer
598 views

Intersymbol Interference — Root raised cosine filter redundant if doing impulse response equalization?

I'm implementing DBPSK (differential binary phase-shift keying) over audio (44.1kHz sample-rate) using software. Eventually I'll use multiple audio frequencies at once, so I'm using FFTs and inverse ...
2
votes
1answer
438 views

DPSK vs PSK Error Probability

BACKGROUND The bit error probability for BPSK under AWGN is easily derived from tail probabilities of Gaussian distributions and results in $$P_e = Q\biggr(\sqrt{\frac{2E_b}{N_o}}\biggl)$$ The ...
2
votes
1answer
3k views

Rectangular 8 QAM bit error rate calculation

I am simulating an 8-QAM communication system over an AWGN channel for various signal to noise ratios, in order to plot the average bit error. However I have not been able to derive an equation for ...
2
votes
1answer
744 views

Non-coherent receiver for DBPSK: Implementation details

I am implementing a non-coherent receiver for DBPSK. I have a computer science background with little knowledge of DSP so my questions here may seem obvious. The design of the receiver I am trying to ...
2
votes
1answer
113 views

Root raised cosine parameter

I try to create matched filter for receive BPSK signal. Sampling rate of the signal is 228000 Hz, data rate 1187.5 symbols/sec, signal was shaped using root raised cosine filter with rolloff factor = ...
2
votes
0answers
88 views

How to find the noise power in my simulation

I am currently working a tricky communication chain that I want to simulate into Matlab. The chain is like a classic BPSK modulator/demodulator chain, but where the BPSK modulated signal has been ...
2
votes
0answers
95 views

Designing a PI filter for a Costas Loop

I am currently trying to implement a Costas Loop in order to demodulate a BPSK signal. Here is the reference block diagram I have been using to design the loop:Costas Loop Block Diagram I originally ...
2
votes
0answers
63 views

GPS CDMA signal acquisition (BPSK modulation)

Sorry, this may be a rookie question: I have a CDMA gps communication in BPSK. Codes have a duration equal to $1\ \text{ms}$ and their length is 1023. At the carrier frequency ($f_c = 1.57524\ \text{...
2
votes
0answers
116 views

Having trouble transmitting/receiving a BPSK signal using two USRPs

I am relatively new to working with SDRs and GNURadio and I am attempting to generate a BPSK signal and transmit it through one USRP and receive and demodulate it on another USRP. I am using GNURadio ...
2
votes
1answer
846 views

QPSK Data Rate vs Bandwidth at Passband: Why can it only transmit 1 bit per Hz and not 2 bits per Hz?

1) This is a follow up question to the most up-voted answer to this question. 2) The accepted answer is that "QPSK transmits 1 bit per Hz at passband". 3) The theory found in books seems to agree ...
2
votes
0answers
168 views

How does a Costas Loop lock to one of multiple BPSK signals

I've been looking into how GPS receivers work in terms of signal processing. When a GPS receiver tracks the received signal, it often uses a Costas loop to synchronize the carrier. How that works ...
1
vote
1answer
1k views

Beginner BPSK demodulation question

I'm writing a simple application in Python that sends and receives data over binary PSK using audio signal. I used cos() for 0 and -cos for 1. On the receiver side I figured I can demodulate by ...
1
vote
3answers
314 views

Bpsk demodulator implementation

For a project I'm trying to implement a BPSK demodulator on some random wave files, I'm getting a few difficulties: How do I know my bit rate, i.e. how many bits each 'real data bit' I'm having. How ...
1
vote
1answer
770 views

GPS Coarse Acquisition PRN Codes

Are the actual 1023 bit sequences for each of the 32 GPS satellites available to consumers? I found the IS GPS 200 but it doesn't list the entire sequences. Are verified sequences available for ...
1
vote
1answer
312 views

Finding $E_b/N_0$ when coding rate is $R_c$

I would like to calculate $E_b/N_0$ when the code rate is $R_c$ for BPSK signal. What I got this $$ E_b/N_0= \frac{1}{2R_mR_c \sigma^2} $$ and that is the case also according to this page. $R_m=1$ ...
1
vote
1answer
188 views

Frequency Hopping Spread Spectrum Synchronization Methods

Frequency-hopping spread spectrum waveforms change the carrier frequency at some interval. I can see if the frequency is constant for the duration of an entire packet, the pilot symbols could be used ...
1
vote
2answers
566 views

What is the maximum data rate a wireless link can support using BPSK for given BER and SNR?

What is maximum data rate a wireless link can support using BPSK for 10^-6 BER, Bandwidth of channel is 200 kHz and SNR ...
1
vote
2answers
3k views

Why do you get instantaneous phase by calculating correlation with a carrier signal?

I am somewhat new to DSP. I'm trying to implement BPSK by following this Python QAM tutorial. My code seems to work, but I really just ported the tutorial's Python code to C++, and do not understand ...
1
vote
1answer
27 views

Modulation classification via demodulation confidence?

I'm not sure if this is the right place to post this question, but will try anyway :-) I recently started reading up on the field of automated modulation classification (AMC) where an algorithm ...
1
vote
1answer
223 views

About the BPSK signal waveform

My basic knowledge is too bad. I am confused about the waveform of BPSK signals. To create a BPSK signal, I generated BPSK symbols with ideal rectangle pulse shaping, which is given by: Then, the ...
1
vote
1answer
423 views

How to properly filter a BPSK demodulated signal?

I am new to this field and yesterday I began a project for BPSK modulation. So this is what i did: $\ x(t) = 0 $ or$\ 1 $ binary data $\ Fs = 15 $ sampling frequency kHz $\ Fc = 10 $ carrier ...
1
vote
1answer
2k views

Adding AWGN noise with a correct noise power to the signal

I would like to add AWGN noise to my BPSK and QPSK signal. So assume the BPSK signal is x1 and QPSK signal is x2. The ...
1
vote
1answer
190 views

Periodically-varying phase between transmitted sound and received sound

I have a function that can find the phase difference between two signals, this function uses Hilbert transform to do so. Here is the python code for it ...
1
vote
1answer
38 views

Meaning of AWGN complex and real noise under BPSK Decision Scheme

I'm currently studying error correcting codes and decided to replicate some common Bit Error Rate curves under BPSK modulation. I initially had trouble to convert SNR to a Gaussian $\sigma$ because I ...
1
vote
1answer
96 views

How to demodulation BPSK in real case(through a channel)?

I am configuring a channel sounding system. Using PRBS to correlate for time delay. Some details as follow. Generate PRBS. Using BPSK to modulate PRBS and Tx transmit. Rx receive signal and ...
1
vote
0answers
63 views

Pulse shape estimation

Given a captured noisy BPSK signal, how do I formulate the maximum-likelihood problem so as to estimate the matched filter? The model of interest would be baseband BPSK with AWGN: $$c(t) = \sum_{\ell=...
1
vote
0answers
223 views

How to find frequency and phase shift in the recorded wave( .wav file )

I am working on BPSK at frequecies near 20 kHz with a sample rate of 44100 Hz. We can't afford sample rates above than this due to computational complexities. Have found that the frequency of ...
1
vote
0answers
81 views

What effect does mutipath have on estimating optimal sampling time using the averaging method described therein

This question takes off from this question regarding syncronization of BPSK signals. For the sake of argument let us assume 10 samples make up 1 bit. One method currently suggested is break up the ...
0
votes
1answer
2k views

Matlab : Adding noise with regard to signal-to-noise ratio or EbNo?

A signal x takes values from an alphabet set. My objective is to estimate the channel parameters hest using adaptive methods and ...
0
votes
3answers
904 views

Processing OBPSK as OQPSK

I'm trying to create and process an OBPSK signal, which, as I understand it, transmits even bits on one axis and the odd bits on the opposite axis, resulting in a constellation with 4 unique points. ...