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Hi
What is the transmission rate for BPSK,QPSK and QAM in WARP design?
Thanks
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The actual over-the-air data rate depends on a number of parameters. You can compute it with:
bitsPerSymbol * symbolsPerOFDMframe * 1/samplesPerOFDMframe * samlpesPerSecond
For the OFDM reference design v07:
bitsPerSymbol = [1, 2, 4] (BPSK, QPSK and 16-QAM)
symbolsPerOFDMframe = 48 (48 subcarriers have data symbols)
samplesPerOFDMframe = 80 (64 subcarriers + 16 sample cyclic prefix)
samplesPerSecond = 10M (effective sampling rate in/out of PHY)
So for QPSK, the over-the-air PHY data rate is 12Mbps.
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I'm trying to figure out PHY transmission time for a certain sized packet. Let's say we have an Ethernet packet of 1000 bytes, QAM16 for fullrate, OFDM reference design v04.
OFDM symbols: 1000/24 = 42
Samples: 42*80 = 3360
So, total samples are:
Preamble: 320
Training: 160
Baserate: 160 (24 bytes with QPSK)
Fullrate: 3360
which means a total of 4000 samples and 400 us for the phy transmission time if the sampling rate is 10Msamples/s. Are these calculations correct?
And, is there any convolutional coding being used?
Thanks
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The wireless MAC adds its own header to the payload taken from Ethernet:
Wireless MAC header: 24 bytes (before payload) modulated at base-rate
Wireless CRC: 4 bytes (after payload) modulated at full-rate
Also, in ref design v04, the over-the-air bandwidth is 12.5MHz (50MHz master clock / 4), so the sample period is 80ns, not 100ns. Otherwise, everything you calculated is correct.
The current ref designs do not include coding. We will add this in a new ref design soon.
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