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PSoC 4 MCU

Anonymous
Not applicable

I need to implement BPSK modulator and demodulator and I'm having a few issues.

1) Is there a way to trigger DMA channel without use of PWM? It just doesnt let me connect clock directly to triger input.

2) I can't seem to find any substitution for Analog Mixer. Is there a way to implement his function with some other component?

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Honored Contributor II

kristijan,

I did not implemented BPSK myself, so I can only provide general advise. I looked around and found a variety of approaches. I believe that at 20kHz carrier frequency the P4200 resources are enough to directly sample input signal and to extract quadrature components (I/Q). Some code examples can be found on TI website (code attached, unchecked)

MSP432P401R: BPSK Modulation/Demodulation - MSP Low-Power Microcontroller Forum - MSP Low-Power Micr...

And another code from TI here:

CCS/TMS320C6713B: Modulation and Demodulation (BPSK) using C6713 - C67x Single Core DSP Forum - C600...

There are some matlab examples on stack exchange like that, which are quite explanatory

digital communications - Simulating BPSK Costas Loop in Matlab - Signal Processing Stack Exchange

/odissey1

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5 Replies
Honored Contributor II

1. What is the carrier frequency?

2. Why not PSoC5?

/odissey1

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Anonymous
Not applicable

Carrier frequency is arround 15-20 kHz.

It wasn't the technology i chose. I got this board to make project with it from my university. It got chosen because it has stable clock frequencies. So I need to implement it with this board.

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Honored Contributor II

Start with sine output project examples from this thread (RAM-DMA-DAC). This will assist you to make a BPSK transmitter. You would likely have to configure two DMA  channels (second one with offset of 180 deg) to transmit 0 and 180 phase.

Whether you will be able to implement a BPSK receiver on the same PSoC4, that is the wuesques, due to limited resources.

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Anonymous
Not applicable

I managed to implement transmitter using two descriptors in DMA controlled with software.

Receiver is problematic because of missing analog mixer. Do you have any idea how I might implement it without mixer? Because it seems to me that mixer is essential part. I'm trying to make it coherent but if it's impossible I'm open to noncoherent demodulation.

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Honored Contributor II

kristijan,

I did not implemented BPSK myself, so I can only provide general advise. I looked around and found a variety of approaches. I believe that at 20kHz carrier frequency the P4200 resources are enough to directly sample input signal and to extract quadrature components (I/Q). Some code examples can be found on TI website (code attached, unchecked)

MSP432P401R: BPSK Modulation/Demodulation - MSP Low-Power Microcontroller Forum - MSP Low-Power Micr...

And another code from TI here:

CCS/TMS320C6713B: Modulation and Demodulation (BPSK) using C6713 - C67x Single Core DSP Forum - C600...

There are some matlab examples on stack exchange like that, which are quite explanatory

digital communications - Simulating BPSK Costas Loop in Matlab - Signal Processing Stack Exchange

/odissey1

View solution in original post

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