Questions tagged [preamble]
The preamble tag has no usage guidance.
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Cross correlation of OFDM short preamble produces two peaks
I am trying to cross correlate the short preamble of an OFDM transmission. This is the preamble I am using:
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How to implement a Basic Embedded Python block in GNU Radio flowgraph?
I am trying to create a GNU Radio flowgraph for identifying a predefined preamble in satellite telemetry packets. For instance, the preamble can be "SAT_SAYS_HI". After identifying this ...
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Preamble generation of narrowband signals
I have to generate a complex sine wave with a sampling frequency of 1.92MHz and subcarrier spacing of 3.75kHz. The number of FFT points is 512. The narrowband frequency is 180kHz.
I also have to ...
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Legacy LongRange Mode information (mode 1 in the my attached link)
Mode 1- Legacy Long Range Packet Format and Im attaching a photo of ti reference:
link for more information about this mode category : TI SWRA642
I want to understand the packet format, what's my ...
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129
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How to check my CRC of my RF packet? [duplicate]
The "problem" is that I want to validate if my received RF packet is valid or not valid, in other words I want to validate if my RF packet corrupted or not corrupted .
the transmitter that ...
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88
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LPF Filtering without changing DC value of signal
I have sampled my transmitted signal, it's looks like sinusoidal , frequency sampling is =2048Khz, bitrate of transmittion=100Kbaud , and my problem is that I have designed in matlab my LPF filter ...
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271
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Matched filter for recieved RF digital packet by LPF
Im transmitting by cc1350 launchpad microprocessor digital RF Packets, transmitted modulation FSK. bit rate of transmitting is 50Kbouad, frequency of transmitting is 868MHZ . Im sampling the signal(...
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104
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filtering my received Signal by LPF
I've received my transmitted signal that I sampled it on 20480000 frequency , transmitted frequency 868MHZ , bitrate 100KHZ , I see the "bits" that Im transmitting in my plot in matlab it ...
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packet encoder RF packets by using LPF for determining if it's zero or one [closed]
I'm transmitting RF packets with frequency 868MHZ ,
symbol rate (it's the same as bit rate) is 50KBaud , and Im sampling them by a dongle (fs=20480KHZ) to capture those RF packets, the captured ...
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72
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Deciding if the received packet is valid or not valid [closed]
I have sampled RF wireless packets as IQ samples file, those RF packets has patterns like preamable|syncword|data|crc , I'm doing cross correlation with my constant syncword (after I did the ...
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209
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Find Syncword (pattern) in signal, using Correlation
I have a signal which always has the same syncword ([93 0b 51 de] in hexa).
I also have a signal with additive noise(attacing it, and I want to find my syncword in that a noisy signal using corelation(...
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288
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Preamble length and channel estimation
For OFDM we select the known gold sequence as the preamble or pilots. We can correctly estimate the channel(10 to 20taps).
Is there any relationship between the length of preamble and the number of ...
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610
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Preamble detection using cross-correlation
I am generating a preamble with a sequence of [1 -1 1 -1 1 -1....] and spread with a barker-11 sequence. Now, the transmitted signal becomes [B(Barker), -B(Inverse of Barker), B, -B,....]. In channel, ...
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Preamble Detection and Frequency Offset Estimation in radio packets
I have generated a radio packet of data with a preamble header of 0x55555555 and crc32 for the data only.
The entire packet was separated in even and odd streams for I and Q. The I and Q were ...
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609
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Why are the mark and space tones of these FSK signals reversed?
I'm working on a project involving FSK-modulated signals. I'm trying to reverse-engineer these signals to determine the preamble pattern used, because the protocol is proprietary.
Shown below is a ...
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gnuradio: How can I change the value of the tag exiting the "Correlate Access Code - Tag" block?
Background: I have built a conventional demodulator in gnuradio and am trying to send payload data out of the flowgraph to an external Python script. I'm using gnuradio v3.7.12.
It seems to me that ...
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OFDM Preamble Ripple Structure in Frequency Domain [closed]
After performing a time and frequency tuning of a signal, and plotting the result in frequency domain(abs value), the following ripple structure can be witnessed.
The extracted bits are LFSR sequence(...
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103
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Spectrum Sensing HW
I am interested to use an existing hardware to perform a spectrum sensing/monitoring in the frequency range of 2.2–2.6 GHz.
Taking into account that the 802.11ac channels are in the range of 2.4–2.5 ...
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3k
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Find Preamble (pattern) in signal, using Corelation
I have a signal which always has the same preamble (4x 0xAA - 10101010...).
I also have a signal with additive noise, and I want to find my preamble in that a noisy signal using corelation.
U used ...
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