Struct Css 

pub struct Css {
    pub sf: u32,
    pub oversampling: usize,
    pub waveform: Waveform,
    pub sample_rate: Hertz,
}

A chirp spread-spectrum link (see the module): a configuration with public fields, built by Css::lora and changed by struct update, checked by Css::check when it is used.

Fields

sf: u32

Spreading factor: M = 2^SF chips per symbol.

oversampling: usize

Samples per chip (1: the chip rate B).

waveform: Waveform

The family of waveforms.

sample_rate: Hertz

The sample rate of the signal of the verb traits, J times the chip rate B (1 Hz by default: time in samples).

Implementations

impl Css

pub fn lora(sf: u32) -> Result<Css>

The LoRa waveform at one sample per chip, at 1 Hz.

Errors

As Css::check: the spreading factor lies in 1..=16.

Examples

use comnum_waveform::css::Css;
let css = Css { oversampling: 4, ..Css::lora(7)? };
assert_eq!(css.symbol_len(), 4 * 128);
assert!(Css::lora(17).is_err());

pub fn m(&self) -> usize

The number of symbols (and of chips per symbol) M = 2^SF.

pub fn symbol_len(&self) -> usize

Samples per symbol, J M.

pub fn check(&self) -> Result<()>

Check the configuration.

Errors

comnum_core::Error::Config unless the spreading factor lies in 1..=16, the oversampling factor is at least 1 (exactly 1 for the FSK reference) and the sample rate is positive and finite.

pub fn symbol(&self, a: usize) -> Result<Vec<C64>>

The J M samples of symbol a.

Errors

comnum_core::Error::Config for invalid parameters or a ≥ M.

pub fn modulate(&self, symbols: &[usize]) -> Result<Vec<C64>>

The samples of a sequence of symbols (the chirps tabulated once, see the module).

Errors

comnum_core::Error::Config for invalid parameters or a symbol ≥ M.

pub fn energies(&self, r: &[C64]) -> Result<Vec<f64>>

The energy of the M candidate symbols of every received symbol: the squared magnitudes of the DFT of the dechirped samples, bins a and, when oversampled, a - M (after the fold) added.

Errors

comnum_core::Error::Config for invalid parameters, comnum_core::Error::Shape for a number of samples that is not a multiple of J M.

pub fn demodulate(&self, r: &[C64]) -> Result<Vec<usize>>

The noncoherent decisions: the candidate of largest energy in every symbol.

Errors

As Css::energies.

pub fn interferer(&self, s1: usize, s2: usize, tau: f64) -> Result<Vec<C64>>

One symbol of an interferer of the same spreading factor, not synchronised: the end of its symbol s1 then the start of its symbol s2, which begins tau chips after the symbol of interest, 0 ≤ tau < M (Afisiadis et al. 2020, eq. (21)), at one sample per chip.

Errors

comnum_core::Error::Config for another waveform than LoRa at one sample per chip, symbols ≥ M or tau outside [0, M).

Trait Implementations

impl Clone for Css

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Css

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Demodulate<Labels> for Css

CSS as a Demodulate block: the noncoherent decisions of Css::demodulate on one stream of samples at Css::sample_rate.

fn demodulate_into(&mut self, y: &Signal, out: &mut Labels) -> Result<()>

Errors

comnum_core::Error::Config for several streams or a signal at another sample rate, and the errors of Css::demodulate.

fn demodulate(&mut self, y: &Signal) -> Result<Out, Error>

where Out: Default,

Demodulate y (allocates, calls Demodulate::demodulate_into).

impl Modulate<Labels> for Css

CSS as a Modulate block: one stream of symbol indices into one stream of samples at Css::sample_rate, by Css::modulate.

fn modulate_into(&self, x: &Labels, out: &mut Signal) -> Result<()>

Errors

comnum_core::Error::Config for several streams, and the errors of Css::modulate.

fn modulate(&self, x: &In) -> Result<Signal, Error>

Modulate x (allocates, calls Modulate::modulate_into).

impl PartialEq for Css

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Css