Signal Processing Stack Exchange
Signal Processing Stack Exchange

Questions tagged [communication-standard]

34 questions
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Actual measurements of the influence of fading and multipath on HF radio communication

I'm looking for papers or books that contain actual measurements of the influence one has to expect in HF radio communication. I'm interested in this, because i've simulated the influence of a physical channel using the Watterson Model on the…
Marcel
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Capacity of cascade binary symmetric channels

Let's imagine that we have interconnected in cascade $L$ binary symmetric channels each with the same transition probability $p(y|x) \in \{p, q=1-p\}$, where the output of each BSC is connected to the input of the next. The overall channel is also a…
CristoJV
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How to determine the FFT size of LTE downlink receiver?

I'm puzzled about the LTE FFT size. Assuming an LTE base station works at 20M mode, the FFT size is 2048. Then, many users can be served by this base station. Do all these users work at 20M mode (i.e., the FFT size of all these users are also…
nnnmao
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System Frame Number in LTE Specifications

What exactly is System Frame Number in LTE specifications? What is the use of it? I have read that it is a 10 bit number and used for synchronization purposes. But it's not clear how it helps for synchronization. Any help is appreciated.
spectre
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P2 symbol constellation in DVB-T2

DVB-T2, 32K SISO, not extended. I've acquired P2 symbol, PRBS bits have matched with bits recovered from pilots. Then equalization was applied to all subcarriers. The constellation I've got looks exactly like rotated 16-QAM overlapped with…
z3dd
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Did Dialup Modem use closed or open loop power/volume control? How did they determine Tx level?

I have been reading about dialup modems, but one thing I cannot seem to find out about is how implementers determined optimal transmit power/volume. Is this part of the echo cancelation framework? The block diagrams I have seen describing echo…
Liam Kelly
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In wireless communications, is it true to say: The more the range, the more the delay spread?

The general idea which can be drawn by reviewing wireless channel models says that the longer the range/distance, the more the delay spread, even in LOS microwave links. But I really wonder why it is true because by simple geometry, supposing a…
Ali
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What is the forward error correction in 802.11a?

I am trying to put together a baseband-equivalent simulation of 802.11a signals, which according to Wikipedia has a variable encoding (PSK, QAM, etc.) that have differing coding rates (1/2, 2/3, 3/4) depending on the choice of RATE bits. I can't…
Andrew
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Convolutional coding that payload length does not change

This is the question about Sigfox radio specification. The stack: Specifically, in Section 3.10 of the specification, we have a convolutional coding (after CRC) with three possible polynominals. I am wonder whether really error correcting code…
Rokai
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What is the difference between Antenna port and Physical Antenna in LTE?

I have just started working on the 5G NR physical layer and I have difficulty understanding the concept of Antenna Port at the downlink. In release 10 there supposedly 15-22 antenna ports for CSIRS (Channel State Information Reference Signal) and…
Mayank
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How often do a LTE eNodeB scheduler schedule?

Scheduler schedules the resource for each UE. How often do a LTE eNodeB scheduler schedule? Is the time between each scheduling fixed? any idea/reference will be great help on this regard. Thanks.
pikapika00
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OFDM Query : Why In Phase and Quadrature Phase RF Conversion is needed?

OFDM Basic Query- x[n] produced at output of IFFT is in discrete time, so we can use DAC and then RF Upconversion (multiply it with LO Frequency say f) and send it, why are we doing RF up conversion in Inphase and Quadrature phase then adding it and…
Reddi Suresh
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NR PUSCH non-codebook based precoding

While reading 3gpp 38.211, Chapter 6.3.1.5 I noticed For non-codebook-based transmission, the precoding matrix equals the identity matrix. So, I guess, non-codebook-based precoding shall be implemented somewhere else but I couldn’t find where. No…
Dmitriy
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5G uplink switching from CP OFDM to DFT-s-OFDM

5g NR standards can allow for both CP-OFDM and DFT-s-OFDM in the uplink. Suppose a UE is allocated resources. Can the UE switch from CP-OFDM to DFT-s-OFDM from one slot to the next ? Are these possible in the same connection ( same PUSCH allocation)…
user59785
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How to find the bandwidth of the transmitted M-FSK signal?

I'm tried to find the solution, but I failed. my question in the figure below, and the correct answer it's shown at the end of Figure. I'm using this formula but the answer is not correct! Is there another solution to this question?
Abdallah_98
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