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Reducing Preamble to increase the effective data rate
#1
Hi,

I want to use the DWM1000 UWB module for data transmission and receiving having a dedicated transmitter and a dedicated receiver. the goal is to get high Data Throughput rates for continuous transmission of physiological data. Sampling rates of 20kSamples / sec per channel where every sample is 16 bits or 2 Bytes of data. 
I want to utilize the 6.8Mbps data rate however I found that the preamble uses up a lot of this data rate (more than half) during transmission. Is there a way to reduce the preamble so that more data can be sent over the UWB transmitter? 

Any thoughts on this are appreciated.
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#2
(02-27-2018, 07:51 PM)mustafak Wrote: Hi,

I want to use the DWM1000 UWB module for data transmission and receiving having a dedicated transmitter and a dedicated receiver. the goal is to get high Data Throughput rates for continuous transmission of physiological data. Sampling rates of 20kSamples / sec per channel where every sample is 16 bits or 2 Bytes of data. 
I want to utilize the 6.8Mbps data rate however I found that the preamble uses up a lot of this data rate (more than half) during transmission. Is there a way to reduce the preamble so that more data can be sent over the UWB transmitter? 

Any thoughts on this are appreciated.

Hi,

Were you able to find a solution to this? I'm running into the same issue.
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#3
For short range the DW1000 can use the 64 length preamble. See Datasheet/UM/ API & examples on this. Have you tried it ?
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#4
(02-27-2018, 07:51 PM)mustafak Wrote: Hi,

I want to use the DWM1000 UWB module for data transmission and receiving having a dedicated transmitter and a dedicated receiver. the goal is to get high Data Throughput rates for continuous transmission of physiological data. Sampling rates of 20kSamples / sec per channel where every sample is 16 bits or 2 Bytes of data. 
I want to utilize the 6.8Mbps data rate however I found that the preamble uses up a lot of this data rate (more than half) during transmission. Is there a way to reduce the preamble so that more data can be sent over the UWB transmitter? 

Any thoughts on this are appreciated.

You can reduce the preamble to 64 bits but no matter what you do if you are transmitting 2 bytes of data per packet your efficiency is going to be terrible. 


Can you cope with a little bit of latency in the system? Group them into blocks of 20 samples and send a 40 byte packet every 1 ms?
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#5
(07-31-2018, 09:20 AM)AndyA Wrote:
(02-27-2018, 07:51 PM)mustafak Wrote: Hi,

I want to use the DWM1000 UWB module for data transmission and receiving having a dedicated transmitter and a dedicated receiver. the goal is to get high Data Throughput rates for continuous transmission of physiological data. Sampling rates of 20kSamples / sec per channel where every sample is 16 bits or 2 Bytes of data. 
I want to utilize the 6.8Mbps data rate however I found that the preamble uses up a lot of this data rate (more than half) during transmission. Is there a way to reduce the preamble so that more data can be sent over the UWB transmitter? 

Any thoughts on this are appreciated.

You can reduce the preamble to 64 bits but no matter what you do if you are transmitting 2 bytes of data per packet your efficiency is going to be terrible. 


Can you cope with a little bit of latency in the system? Group them into blocks of 20 samples and send a 40 byte packet every 1 ms?

Reducing my latency as much as possible is my goal at the moment, I've used the shortest preamble and played around with the other possible settings however the latency is still far too high. Is it possible to remove the error checking perhaps in order to decrease the overall latency between transmit and receive?
MikeF, proud to be a member of Decawave Tech Forum since Jul 2018.
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#6
(08-09-2018, 05:08 PM)MikeF Wrote:
(07-31-2018, 09:20 AM)AndyA Wrote:
(02-27-2018, 07:51 PM)mustafak Wrote: Hi,

I want to use the DWM1000 UWB module for data transmission and receiving having a dedicated transmitter and a dedicated receiver. the goal is to get high Data Throughput rates for continuous transmission of physiological data. Sampling rates of 20kSamples / sec per channel where every sample is 16 bits or 2 Bytes of data. 
I want to utilize the 6.8Mbps data rate however I found that the preamble uses up a lot of this data rate (more than half) during transmission. Is there a way to reduce the preamble so that more data can be sent over the UWB transmitter? 

Any thoughts on this are appreciated.

You can reduce the preamble to 64 bits but no matter what you do if you are transmitting 2 bytes of data per packet your efficiency is going to be terrible. 


Can you cope with a little bit of latency in the system? Group them into blocks of 20 samples and send a 40 byte packet every 1 ms?

Reducing my latency as much as possible is my goal at the moment, I've used the shortest preamble and played around with the other possible settings however the latency is still far too high. Is it possible to remove the error checking perhaps in order to decrease the overall latency between transmit and receive?

Playing with the internal structure of the frame is unlikely to work. That will be a fundamental assumption of the silicon, the physical layer is part of the IEEE specification.

If you send frames of 4 bytes (two samples) then each frame will be a minimum 105 us long giving a maximum of around 19k samples per second.

If you were to group up chunks of 8 samples that gives you a packet of 16 bytes which will take 117 us to transmit.
If you sent one of those every 200 us you'd get your 40k samples a second with a maximum latency of around 320 us. I don't think you're going to get much better than that.
AndyA, proud to be a member of Decawave Tech Forum since Jun 2018.
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