Phase shift keying | Cypress Semiconductor
Phase shift keying
I'm trying to implement phase-shift keying on the PSoC 5 (http://en.wikipedia.org/wiki/Phase-shift_keying). I'm looking to implement both the modulator and de-modulator. I would love to implement as much as I can in hardware. I've come across AN60594 (http://www.cypress.com/?rID=40985) which provides a really elegant example of how to implement frequency shift keying (FSK) in hardware.
Since QPSK modulation is more complicated, I will likely start with BPSK. I think the modulator would be somewhat easy. I am planning on connecting a UART output to to a WaveDAC8 component (ANAN69133) to switch between two sinusoidal outputs of varying phases. I would appreciate any other ideas.
For the de-modulator I'm currently a bit stumped. AN60594, above, uses a very elegant solution for FSK, in which the author XORs the incoming signal with a delayed version of the same signal. The result is then low-pass filtered and gives the desired bit-stream. Everything is done in hardware. Would it be possible to do something similar for PSK? I was thinking of matching the incoming signal with a sine wave of the same frequency and then performing some sort of difference operation. I'm not sure how best to do something like this.
I would love to minimize the amount of software operations and do as much as possible in hardware. Any ideas would be much appreciated. Thank you,