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软件无线电的平台

synch
=====


 Before two mobiles can communicate together, they need to have a common
time. This is usually done with a synchronisation-signal sent by one
mobile, that is picked up by another, which then synchronises on this
signal. In 3GPP, this is called 'primary synchronisation'.
 There is one synch_send, but one synch_rcv for each of:
- STM-cards
- complex-cards (which never existed)
- ICS-cards
 This is due to the different data-structures from each of the cards, and
the fact that the synchronisation is best done on the raw signal...


synch_complex_ics_rcv
---------------------

 The desynchronisation uses a convolution to find the most probable
synchronistaion-signal. Due to the special format of the synch-signal,
it is possible to implement this as two convolutions, which reduces a
lot the computational complexity of the task.
 This is adjusted for input of a ICS-card.

Inputs:
	SYMBOL_COMPLEX_S32

outputs:
	SYMBOL_COMPLEX_S32

Config:
	fine_adj<int>: 0
		If this is 1, the sycnh_rcv also sets the offset_samples_rcv of the stfa

	mean<int>: 1
		Mean over this many slots to take the synchronisation

	skip<int>: 10
		Skip synchronisation if more than this number of other high peaks.
		Useful numbers start at 5, 10 is a good bet.

	stfa_id<int>: -1
		If this is set to a valid id, it will set the offset for the stfa


Stats:
	buffer<block_t>:
		The internal buffer - not really interesting

	fine_amp<int>:
		The fine amplitude

	fine_pos<int>:
		The fine position, 0-3

	mean<int>:
		The actual mean - debug

	synch<block_t>:
		The synchronisation signal - OK to look at it

	synch_amp<int>:
		The amplitude of the strongest signal

	synch_pos<int>:
		The position of the strongest synchronisation signal


synch_complex_rcv
-----------------

 The desynchronisation uses a convolution to find the most probable
synchronistaion-signal. Due to the special format of the synch-signal,
it is possible to implement this as two convolutions, which reduces a
lot the computational complexity of the task.
 This is different in that it takes a complex input.

Inputs:
	SYMBOL_COMPLEX

outputs:
	SYMBOL_COMPLEX

Config:
	fine_adj<int>: 0
		If this is 1, the sycnh_rcv also sets the offset_samples_rcv of the stfa

	skip<int>: 10
		Skip synchronisation if more than this number of other high peaks.
		Useful numbers start at 5, 10 is a good bet.

	stfa_id<int>: -1
		If this is set to a valid id, it will set the offset for the stfa


Stats:
	buffer<block_t>:
		The internal buffer - not really interesting

	fine_amp<int>:
		The fine amplitude

	fine_pos<int>:
		The fine position, 0-3

	synch<block_t>:
		The synchronisation signal - OK to look at it

	synch_amp<int>:
		The amplitude of the strongest signal

	synch_pos<int>:
		The position of the strongest synchronisation signal


synch_rcv
---------

 The desynchronisation uses a convolution to find the most probable
synchronistaion-signal. Due to the special format of the synch-signal,
it is possible to implement this as two convolutions, which reduces a
lot the computational complexity of the task.

Inputs:
	SAMPLE_S12

outputs:
	SAMPLE_S12

Config:
	fine_adj<int>: 0
		If this is 1, the sycnh_rcv also sets the offset_samples_rcv of the stfa

	stfa_id<int>: -1
		If this is set to a valid id, it will set the offset for the stfa


Stats:
	buffer<block_t>:
		The internal buffer - not really interesting

	fine_amp<int>:
		The fine amplitude

	fine_pos<int>:
		The fine position, 0-3

	synch<block_t>:
		The synchronisation signal - OK to look at it

	synch_amp<int>:
		The amplitude of the strongest signal

	synch_pos<int>:
		The position of the strongest synchronisation signal


synch_send
----------

 It produces a simple-to retrieve synch-signal on one slot. Contrary to
the 3GPP definition, which has the synchronisation-signal simply added
to the rest of the signal, we explicitly take some place at the beginning
of a slot to put the signal in there.

Inputs:
	SYMBOL_COMPLEX

outputs:
	SYMBOL_COMPLEX

Config:
	amplitude<int>: 32767
		The amplitude of the signal


Stats:
	slots_sent<int>:
		How many slots have been sent already