Constellation Objects & Messages


I’m using the gr-digital constellation decoder block in GRC
(digital_constellation_decoder_cb) with constellation objects such as
digital.constellation_qpsk(), etc.

I want to modify the block such that it accepts a message and from
that message the block can infer which constellation object to use. This
will all be done in the message handler function. So for example:

std::string message = pmt::symbol_to_string(msg);

if(strcmp(message, “BPSK”) == 0)
d_constellation = constellation_bpsk();
else if(strcmp(message, “QPSK”) == 0)
d_constellation = constellation_qpsk();

Any ideas on how to set d_constellation as one of these objects?

It is to operate in an OFDM receiver whereby the header of a packet
transmission is decoded and from that, information about the payload
constellation can be acquired. (802.11)