GNU Radio 3.6.4.2 C++ API
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Polyphase filterbank bandpass decimator with gr_complex input, gr_complex output and float taps. More...
#include <gr_pfb_decimator_ccf.h>
Public Member Functions | |
~gr_pfb_decimator_ccf () | |
void | set_taps (const std::vector< float > &taps) |
void | print_taps () |
int | work (int noutput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items) |
just like gr_block::general_work, only this arranges to call consume_each for you More... | |
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gr_sync_block (void) | |
gr_sync_block (const std::string &name, gr_io_signature_sptr input_signature, gr_io_signature_sptr output_signature) | |
virtual | ~gr_sync_block (void) |
int | general_work (int noutput_items, gr_vector_int &ninput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items) |
implements work -> calls work More... | |
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gr_block (void) | |
gr_block (const std::string &name, gr_io_signature_sptr input_signature, gr_io_signature_sptr output_signature) | |
long | unique_id (void) const |
std::string | name (void) const |
virtual | ~gr_block (void) |
gr_io_signature_sptr | input_signature (void) const |
gr_io_signature_sptr | output_signature (void) const |
void | set_input_signature (gr_io_signature_sptr sig) |
void | set_output_signature (gr_io_signature_sptr sig) |
virtual bool | check_topology (int ninputs, int noutputs) |
virtual void | forecast (int, std::vector< int > &) |
Overload me! I am the forecast. More... | |
virtual bool | start (void) |
virtual bool | stop (void) |
void | consume_each (const int how_many_items) |
Call during work to consume items. More... | |
void | consume (const size_t i, const int how_many_items) |
void | produce (const size_t o, const int how_many_items) |
uint64_t | nitems_read (const size_t which_input=0) |
Get absolute count of all items consumed on the given input port. More... | |
uint64_t | nitems_written (const size_t which_output=0) |
Get absolute count of all items produced on the given output port. More... | |
void | add_item_tag (const size_t which_output, const gr_tag_t &tag) |
void | add_item_tag (const size_t which_output, uint64_t abs_offset, const pmt::pmt_t &key, const pmt::pmt_t &value, const pmt::pmt_t &srcid=pmt::PMT_F) |
void | get_tags_in_range (std::vector< gr_tag_t > &tags, const size_t which_input, uint64_t abs_start, uint64_t abs_end, const pmt::pmt_t &key=pmt::pmt_t()) |
void | set_alignment (const size_t alignment) |
bool | is_unaligned (void) |
size_t | fixed_rate_noutput_to_ninput (const size_t noutput_items) |
size_t | interpolation (void) const |
void | set_interpolation (const size_t) |
size_t | decimation (void) const |
void | set_decimation (const size_t) |
int | max_noutput_items (void) const |
void | set_max_noutput_items (int) |
void | unset_max_noutput_items (void) |
bool | is_set_max_noutput_items (void) const |
unsigned | history (void) const |
void | set_history (unsigned history) |
void | set_fixed_rate (const bool fixed_rate) |
bool | fixed_rate (void) const |
Get the fixed rate setting. More... | |
void | set_relative_rate (const double relative_rate) |
double | relative_rate (void) const |
Get the relative rate setting. More... | |
void | set_output_multiple (const size_t multiple) |
size_t | output_multiple (void) const |
Get the output multiple setting. More... | |
tag_propagation_policy_t | tag_propagation_policy (void) |
void | set_tag_propagation_policy (tag_propagation_policy_t p) |
void | set_max_output_buffer (long) |
void | set_max_output_buffer (int, long) |
long | max_output_buffer (size_t) |
void | set_min_output_buffer (long) |
void | set_min_output_buffer (int, long) |
long | min_output_buffer (size_t) |
std::string | symbol_name () const |
bool | alias_set () |
std::string | alias () |
pmt::pmt_t | alias_pmt () |
void | set_block_alias (std::string name) |
template<typename T > | |
void | set_msg_handler (pmt::pmt_t which_port, T msg_handler) |
void | message_port_register_in (pmt::pmt_t) |
void | message_port_register_out (pmt::pmt_t) |
void | message_port_pub (pmt::pmt_t, pmt::pmt_t) |
void | message_port_sub (pmt::pmt_t, pmt::pmt_t) |
void | message_port_unsub (pmt::pmt_t, pmt::pmt_t) |
virtual bool | message_port_is_hier (pmt::pmt_t port_id) |
virtual bool | message_port_is_hier_in (pmt::pmt_t port_id) |
virtual bool | message_port_is_hier_out (pmt::pmt_t port_id) |
pmt::pmt_t | message_ports_in () |
Get input message port names. More... | |
pmt::pmt_t | message_ports_out () |
Get output message port names. More... | |
bool | empty_p (pmt::pmt_t which_port) |
is the queue empty? More... | |
bool | empty_p () |
void | insert_tail (pmt::pmt_t, pmt::pmt_t) |
pmt::pmt_t | delete_head_nowait (pmt::pmt_t) |
pmt::pmt_t | delete_head_blocking (pmt::pmt_t) |
msg_queue_t::iterator | get_iterator (pmt::pmt_t which_port) |
void | erase_msg (pmt::pmt_t which_port, msg_queue_t::iterator it) |
virtual bool | has_msg_port (pmt::pmt_t which_port) |
bool | has_msg_handler (pmt::pmt_t which_port) |
Tests if there is a handler attached to port which_port . More... | |
virtual void | dispatch_msg (pmt::pmt_t which_port, pmt::pmt_t msg) |
void | set_processor_affinity (const std::vector< int > &mask) |
Set the thread's affinity to processor core n . More... | |
void | unset_processor_affinity () |
Remove processor affinity to a specific core. More... | |
std::vector< int > | processor_affinity () |
Get the current processor affinity. More... | |
void | work (const InputItems &, const OutputItems &) |
implements work -> calls general work More... | |
void | notify_topology (const size_t, const size_t) |
notifications of new topological commits More... | |
void | notify_active (void) |
start notification More... | |
void | notify_inactive (void) |
stop notification More... | |
virtual void | propagate_tags (const size_t, const gras::TagIter &) |
implements tag_propagation_policy() More... | |
void | _update_input_reserve (void) |
gras::BufferQueueSptr | input_buffer_allocator (const size_t, const gras::SBufferConfig &) |
gras::BufferQueueSptr | output_buffer_allocator (const size_t, const gras::SBufferConfig &) |
Friends | |
GR_CORE_API gr_pfb_decimator_ccf_sptr | gr_make_pfb_decimator_ccf (unsigned int decim, const std::vector< float > &taps, unsigned int channel) |
Polyphase filterbank bandpass decimator with gr_complex input, gr_complex output and float taps.
This block takes in a signal stream and performs interger down- sampling (decimation) with a polyphase filterbank. The first input is the integer specifying how much to decimate by. The second input is a vector (Python list) of floating-point taps of the prototype filter. The third input specifies the channel to extract. By default, the zeroth channel is used, which is the baseband channel (first Nyquist zone).
The channel parameter specifies which channel to use since this class is capable of bandpass decimation. Given a complex input stream at a sampling rate of fs and a decimation rate of decim, the input frequency domain is split into decim channels that represent the Nyquist zones. Using the polyphase filterbank, we can select any one of these channels to decimate.
The output signal will be the basebanded and decimated signal from that channel. This concept is very similar to the PFB channelizer (see gr_pfb_channelizer_ccf) where only a single channel is extracted at a time.
The filter's taps should be based on the sampling rate before decimation.
For example, using the GNU Radio's firdes utility to building filters, we build a low-pass filter with a sampling rate of fs, a 3-dB bandwidth of BW and a transition bandwidth of TB. We can also specify the out-of-band attenuation to use, ATT, and the filter window function (a Blackman-harris window in this case). The first input is the gain of the filter, which we specify here as unity.
<B><EM>self._taps = gr.firdes.low_pass_2(1, fs, BW, TB, attenuation_dB=ATT, window=gr.firdes.WIN_BLACKMAN_hARRIS)</EM></B>
The PFB decimator code takes the taps generated above and builds a set of filters. The set contains decim number of filters and each filter contains ceil(taps.size()/decim) number of taps. Each tap from the filter prototype is sequentially inserted into the next filter. When all of the input taps are used, the remaining filters in the filterbank are filled out with 0's to make sure each filter has the same number of taps.
The theory behind this block can be found in Chapter 6 of the following book.
f. harris, "Multirate Signal Processing for Communication Systems," Upper Saddle River, NJ: Prentice Hall, Inc. 2004.
gr_pfb_decimator_ccf::~gr_pfb_decimator_ccf | ( | ) |
void gr_pfb_decimator_ccf::print_taps | ( | ) |
Print all of the filterbank taps to screen.
void gr_pfb_decimator_ccf::set_taps | ( | const std::vector< float > & | taps | ) |
Resets the filterbank's filter taps with the new prototype filter
taps | (vector/list of floats) The prototype filter to populate the filterbank. |
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virtual |
just like gr_block::general_work, only this arranges to call consume_each for you
The user must override work to define the signal processing code
Reimplemented from gr_sync_block.
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friend |
Build the polyphase filterbank decimator.
decim | (unsigned integer) Specifies the decimation rate to use |
taps | (vector/list of floats) The prototype filter to populate the filterbank. |
channel | (unsigned integer) Selects the channel to return [default=0]. |