ldpc==== LDPC codes are Low Density Parity Check codes used in favor ofconvolutional codes. They are quite experimental and not widelytested. Furthermore this module is not optimsed at all!ldpc_decode----------- Tries to decode the received slot. As it is really slow to do this,this module should be SUBS_MSG_THREADed so that it has more than oneslot's time to decode.Inputs:	SYMBOL_COMPLEXoutputs:	U8Config:	channel_param<double>: 0.07		either 'p' for a BSC or 'a/variance' for AWGN	channel_type<int>: 1		The type of channel.		1 - BSC ( Binary Symmetric Channel )		2 - AWGN ( Average White Gaussian Noise )	drop_blocks<int>: 0		How many blocks to drop	iterations<int>: 30		The number of iterations that are done to decode the message.		Each iteration contains a cnode->vnode->cnode cycle	ldpc_code_id<int>: 1		The index of the ldpc-code. For the moment, three codes		are implemented:		1 - rate .25, size 4000		2 - rate .5, size 3992		3 - rate .75, size 3992	mafi<int>: -1		Define the matched filter to calculate the correct a/varianceStats:	snr<double>:		The calculated SNR in case of a AWGN channelldpc_encode----------- Encodes a slot. Needs to have a modulator-module with a QPSKmodulation.Inputs:	U8outputs:	U8Config:	ldpc_code_id<int>: 1		The index of the ldpc-code. For the moment, three codes		are implemented:		1 - rate .25, size 4000		2 - rate .5, size 3992		3 - rate .75, size 3992