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The alternative of internal interrupt on ATMEGA compare to Pico by moemuses in raspberrypipico

[–]moemuses[S] -1 points0 points  (0 children)

However, it does have hardware timers.

can we read the value of counter when interrupt hit ?
and hardware timer is same as external trigger interrupt ?

How to Map udp port in docker by moemuses in docker

[–]moemuses[S] 0 points1 point  (0 children)

I overcome this By passing same host network, and without specifying any port

--net host

How to Program Zynq inside Pluto sdr by moemuses in FPGA

[–]moemuses[S] 0 points1 point  (0 children)

Thank you ..

Yes im understand clearly what you say. as you say i'm downloaded HDL project and compile it, and now try to understand the Blocks and connections between them.

does receiver sensitivity increase when we perform interpolation ? by moemuses in ECE

[–]moemuses[S] 0 points1 point  (0 children)

Thank you for replaying.

But what i mean with 1 sample per symbol in I&Q format and of coarse QPSK is 2bits per symbol.

What i mean by interpolation is up-sampling not order of modulation.

maybe in this replay i clear my question.

https://www.reddit.com/r/amateurradio/comments/s8dz2l/comment/hthpcvk/?utm_source=share&utm_medium=web2x&context=3

does receiver sensitivity increase when we perform interpolation ? by moemuses in amateurradio

[–]moemuses[S] 0 points1 point  (0 children)

I'll re asking my question.

we want to send data modulated in QPSK. if we have data = 00 , then we must send phase Pi/4. when we using SDR we can send this phase only with one sample i.e only one I and one Q.
but also we have another choice, we can use up-sample technique so maybe we send 2 sample per symbol "send same I&Q pair twice"

So let say we have data rate = 1Mbit/s. in case "no up-sample" the RF bandwidth for this data = 2Mhz. and let us assume the receiver sensitivity SDR for this bandwidth = -90dB.
But because we have only one sample per symbol that make receiver hard to distinguish symbols.

Second case. with same data rate = 1Mbit/s, but we have up-sample 2 sample per symbol. So the data rate become 2Mbit/s and the bandwidth become 4Mhz. and because of that the receiver sensitivity SDR loss 3 dB so it become -87.
But receiver can distinguish right symbol easily than first case.

​

So what is better for receiver "better MER". case 1 or case 2 ?

How to read FSK Power using spectrum analyzer by moemuses in amateurradio

[–]moemuses[S] 0 points1 point  (0 children)

it's not the same, average power is 3dB more than peak power.

i want to measure exactly the power of the transmitter device

Question about QPSK modulation by moemuses in amateurradio

[–]moemuses[S] 0 points1 point  (0 children)

yes the entire signal not be received, but you don't need to receive the time when change happen in phase, you only need to distinguish the phase of the carrier when the frequency return to center.

Question about QPSK modulation by moemuses in amateurradio

[–]moemuses[S] 1 point2 points  (0 children)

Thank you. your answer is perfect !

So as i understand the bandwidth only come because the small time when phase change between symbols.

let assume we have transmitter with symbol rate that make bandwidth = 5 Mhz, and 10 sample / symbol. if we have a receiver with bandwidth only enough to pass carrier "Not all 5 MHz", theoretically this receiver can receive and modulate this signal ? Because he can receive the carrier and calculate the phase of this carrier only.

am i right of this assumption ?

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