path: root/Transceiver52M/Resampler.cpp
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2017-06-22sigProcLib: Replace dynamically allocated resampling buffersTom Tsou1-69/+32
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
2017-04-03Resampler: Fix non-array delete for filter tapsTom Tsou1-1/+1
Change-Id: I59cdb01809da5940c74aaae9d17f413aefbf04b2 Fixes: Coverity CID 149349
2017-03-31Resampler: Fix initialization return checkingTom Tsou1-1/+1
Greater-than comparison was used on boolean type. Change-Id: Ia3b71b3a06b34a6fd781bf197ecf9d5cc1711d13
2016-10-26transceiver: Fix mismatched allocations and deallocationspierre.baudry1-1/+1
The behaviour of a mismatched pair of allocation and deallocation is undefined Also fixes a memory leak if malloc fails (which stops the application anyway) Change-Id: I9c8bbade8531e8c9c02dcd43bac38cb954b3c89f
2016-07-01iface: Add inner ring-buffer implementationTom Tsou1-30/+2
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>
2016-03-06EDGE: Add 8-PSK modulator and demodulatorTom Tsou1-7/+20
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>
2013-10-18Transceiver52M: Replace resampler with SSE enabled implementationThomas Tsou1-0/+239
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>