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Phase synchronization in BPSK

Phase (or carrier) Recovery for BPSK can be done over the entire sequence using the information from every sample. Here are common approaches to doing Carrier Recovery: Frequency Doubling (squaring):...
Dan Boschen's user avatar
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9 votes

High modulation index PSK - carrier recovery

A PLL on its own will not work on the direct PSK modulation, assuming the symbols are equi-probable as that results in a nulled carrier, so there is nothing the PLL can track! Costas-Loops are ...
Dan Boschen's user avatar
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8 votes
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Relation between Bandwidth and Baud-Rate for 8-PSK

The final statement is correct, for PSK with proper pulse shaping the baud rate and the bandwidth are the same (the bandwidth will typically be 20-30% higher than the symbol rate, but read on). The ...
Dan Boschen's user avatar
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7 votes
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MATLAB: Adding Noise with Regard to Signal to Noise Ratio (SNR) or EbNo?

These stuffs $E_s/N_0, E_b/N_0 \textrm{ and SNR}$ are convertible. \begin{align} E_s/N_0 &= E_b/N_0 + 10\log_{10}(k) \\ E_s/N_0 &= 10\log_{10}(T_{sym}/T_{samp}) + \mathrm{SNR} \end{align} ...
AlexTP's user avatar
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6 votes
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Beginner BPSK demodulation question

An "integrate and dump" filter is a common approach for this application, which is essentially an averaging filter averaged optimally over your symbol period. To implement this, you simply ...
Dan Boschen's user avatar
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5 votes
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Shannon capacity limit & FEC comparisons

I start with BPSK achieving 1 bits/sec/Hz over passband AWGN. Factoring in 1/3 rate coding this becomes 0.333 bits/sec/Hz. This is not correct. The Shannon noisy channel coding theorem states that ...
AlexTP's user avatar
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4 votes
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Energy per bit ($E_b$) in BPSK with non-unity channel gain

The energy per bit $E_b$ means one thing and one thing only: how many joules is the transmitter spending, on average, per information bit transmitted. Note that the channel has absolutely nothing to ...
MBaz's user avatar
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4 votes

Spectral Effeciency of BPSK

The spectral efficiency depends on the pulse shape. The basepand BPSK signal can be written as $$s(t)=\sum_k a_k p(t-kT_b),$$ where $a_k$ is equal to either $\sqrt{E_b}$ or $-\sqrt{E_b}$, $E_b$ is the ...
MBaz's user avatar
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4 votes
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Finding $E_b/N_0$ when coding rate is $R_c$

The energy per bit, $E_b$, is independent of the coding rate. Note that $E_b$ measures the energy per transmitted information bit, not per transmitted symbol. Let's say you're willing to spend one ...
MBaz's user avatar
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4 votes

why does the decision boundary change in BPSK? is it true?

Zero-mean noise by itself can't modify the decision boundary. However, the number of things that can go wrong in your system is large. Is your channel flat or frequency-selective? You can think of ...
MBaz's user avatar
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4 votes
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GPS Coarse Acquisition PRN Codes

I have a PRN generator that I have validated with live captured signals that is available on the Mathworks Exchange site at this address and equally runs in Octave (Update: I also pasted the core of ...
Dan Boschen's user avatar
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4 votes
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Block diagram of M-PSK modulation and demodulation

So this seems to be a general block diagram for these types of modulations. No, this is a block diagram of a IQ upconverter with some unspecified digital data modulator on the input. You need to ...
Marcus Müller's user avatar
4 votes
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Detection problem with extra noise observation. Does the extra observations help with detection?

$$y=y_1 + \alpha y_2=x+(1+\alpha)n_1+\alpha n_2 \tag{1}$$ As $n_1$ and $n_2$ are iid $\mathcal{N}(0,\sigma^2)$, you have now the new Gausian noise $\mathcal{N}(0,\nu^2)$ where $\nu^2=\left((1+\alpha)^...
AlexTP's user avatar
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3 votes

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

I think it can be misleading to think RRC are used to eliminate ISI. The only purpose of Raised Cosine (RC) and Root-Raised Cosine (RRC) filtering in the transmitter specifically is to constrain the ...
Dan Boschen's user avatar
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3 votes

FFT of BPSK signal interpretation

A random sequence of +1 and -1 is not really a BPSK signal; it's just a sequence of bits. As such, its FFT has not much meaning, at least not in the sense you're thinking of. To create an actual BPSK ...
MBaz's user avatar
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3 votes

Adding AWGN noise with certain power

This is solved slightly differently if you're simulating a continuous-time or discrete-time AWGN channel. I'll assume you're simulating a discrete-time channel; that is, you're simulating the output ...
MBaz's user avatar
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3 votes
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Adding AWGN noise with a correct noise power to the signal

The kind of AWGN channel you're simulating is sometimes called a "discrete time" channel. That means that you're going to simulate the bit error rate at the output of a decision device, the input to ...
MBaz's user avatar
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3 votes
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Is Phase Locked Loop is essential for BPSK signal reception?

There are three different kinds of synchronization in a passband digital communications system: Carrier synchronization: the receiver needs to know the exact frequency and phase of the carrier used ...
MBaz's user avatar
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3 votes
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Phase transitions in GPS C/A signal

That text is confusing on its own as the spectrum spreading as transmitted is NOT affected as described. This is suggesting that if you acquire on any arbitrary 20 ms sequence of received data, your ...
Dan Boschen's user avatar
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3 votes
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Detect low power DSSS-BPSK signal

Without disagreement to Dilip's valid comments, this is to show the corner case as to when you can detect the presence of DSSS. This is not demodulating the data but detecting the presence of a ...
Dan Boschen's user avatar
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3 votes

Phase correction algorithm: minimisation phase error

I commend you for using an intuitive algorithm. However, there are already established algorithms with far better performance. Phase recovery algorithms work by filtering the error signal down to zero....
Moses Browne Mwakyanjala's user avatar
3 votes

Do BPSK vs QPSK have the same performance?

BPSK and QPSK have the same BER performance under additive white Gaussian noise only if the symbols are appropriately mapped to bits (such as Gray coding) since they can be viewed / treated as two ...
Dan Boschen's user avatar
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3 votes
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BPSK consecutive same symbols

The canonical baseband version of BPSK is that we wish to transmit a sequence $\{a_k\}$ of bits ($0$ or $1$) at a rate of $1$ bit every $T$ seconds using a pulse $g(t)$ of duration $T$ and so the ...
Dilip Sarwate's user avatar
3 votes
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QPSK implementation with 2 BPSK

Your constellation points are the sum of {+1, -1} and {+1j, -1j}, so you get the points {+1+1j, +1-1j, -1+1j, -1-1j}, which have these odd multiples of 45° as angles. That's one way to look at it. The ...
Marcus Müller's user avatar
3 votes
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Is BPSK relevant, or does it even exist, in wireless data transmission?

You are mostly correct. The main problem is that the introductory textbook definition of BPSK as a train of square pulses multiplied by a carrier is so simplistic that it hides what is really going on....
MBaz's user avatar
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2 votes
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Bpsk demodulator implementation

You want to take a wav file, run it through a BPSK modulator and I'm guessing (from your #3) to plot some waveform or something. So you should find a wav file like handel.mat which is built into ...
Engineer's user avatar
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2 votes
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Frequency Hopping Spread Spectrum Synchronization Methods

This can be accomplished by changing the carrier frequency using a Numerically Controlled Oscillator (NCO) which maintains an accurate and continuous phase versus time trajectory via the phase ...
Dan Boschen's user avatar
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2 votes

Is there such a thing as a continuous phase BPSK?

You're right that the transitions can be abrupt, but you can always choose to use pulse shaping, i.e., instead of using a rectangular pulse, use some smoother function $p(t)$. The corresponding ...
Matt L.'s user avatar
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2 votes
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DPSK vs PSK Error Probability

The flaw in the problem posed starts right from the block diagram that you have posted: it is not the case in DPSK receiver that the RF signal is multiplied with a delayed version of itself and then ...
Dilip Sarwate's user avatar
2 votes
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Audio signal arrival timing, impulse response, and reverberation

Your problem parallels exactly what we do in seismic exploration, although the scale is different. We also use sound waves, with frequencies of 0-100 Hz, and record times up to about 10 s. A few ...
telemeister's user avatar

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