osmo-trx - OpenBTS transceiver retro-fit

Age	Commit message (Collapse)	Author	Files	Lines
2021-12-14	treewide: remove FSF address2022q1 2021q4	Oliver Smith	1	-4/+0
	Remove the paragraph about writing to the Free Software Foundation's mailing address. The FSF has changed addresses in the past, and may do so again. In 2021 this is not useful, let's rather have a bit less boilerplate at the start of source files. Change-Id: I8ba71ab9ccde4ba25151ecbeb2a323f706b57d43
2019-10-17	Fix common misspellings and typos	Martin Hauke	1	-2/+2
	Change-Id: I4ec7accb1912c052b446be7c399bed32a8c62253
2019-07-22	Add SPDX annotation	Pau Espin Pedrol	1	-0/+2
	Related: OS#3515 Change-Id: I3719bd8dc015569ecd81928fc079e27593cdca09
2019-07-22	cosmetic: Fix trailing whitespace in several files	Pau Espin Pedrol	1	-2/+2
	Change-Id: Ifafb68353960fc5046661854ccfb8d783b0efb14
2017-06-22	sigProcLib: Replace dynamically allocated resampling buffers	Tom Tsou	1	-7/+7
	Instead use object allocated STL vectors. This simplifies code, removes the need to explicitly release buffers, and fixes a memory leak in destructor deallocation. Also, remove simplified init and release sub-calls. Maintain partition filter allocation using memalign() for SIMD alignment requirements. Change-Id: Ie836982794c10fb1b6334e40592d44b200454846
2016-07-01	iface: Add inner ring-buffer implementation	Tom Tsou	1	-8/+1
	Two buffers, inner and outer, are used in the transceiver implementation. The outer buffer interfaces with the device receive interface to guarantee timestamp aligned and contiguously allocated sample buffers. The inner buffer absorbs vector size differences between GSM bursts (156 or 157 samples) and the resampler interface (typically fixed multiples of 65). Reimplement the inner buffer with a ring buffer that allows fixed size segments on the outer (resampler) portion and variable lengths (GSM side) on the inner side. Compared to the previous stack-like version, this implementation removes unnecessary copying of buffer contents. Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
2016-03-06	EDGE: Add 8-PSK modulator and demodulator	Tom Tsou	1	-0/+6
	Setup correlator and detection process similar to the GMSK receiver chain. Require 4 SPS sampling on both Rx and Tx paths as 1 SPS sampling adds too much distoration for 8-PSK recovery. Core receiver operations still run at 1 SPS with the exception of fractional delay filtering, which runs at the higher rate. Perform linear equalization to handle the Gaussian pulse induced ISI. The fixed impulse response used for equalizer tap calculation consists of combined EDGE pulse shape filter and effects of the downsampling filter. Note that the non-adaptive equalizer corrects for modulation induced band limiting and does not account for or compensate for fading channel effects. Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
2013-10-18	Transceiver52M: Replace resampler with SSE enabled implementation	Thomas Tsou	1	-0/+77
	Replace the polyphase filter and resampler with a separate implementation using SSE enabled convolution. The USRP2 (including derived devices N200, N210) are the only supported devices that require sample rate conversion, so set the default resampling parameters for the 100 MHz FPGA clock. This changes the previous resampling ratios. 270.833 kHz -> 400 kHz (65 / 96) 270.833 kHz -> 390.625 kHz (52 / 75) The new resampling factor uses a USRP resampling factor of 256 instead of 250. On the device, this allows two halfband filters to be used rather than one. The end result is reduced distortial and aliasing effecits from CIC filter rolloff. B100 and USRP1 will no be supported at 400 ksps with these changes. Signed-off-by: Thomas Tsou <tom@tsou.cc>