rx: reset internal state when restarting after a transmission

This commit is contained in:
Thomas Kolb 2024-05-28 19:55:21 +02:00
parent d5aeb6c0bc
commit 91facbf699
5 changed files with 55 additions and 1 deletions

View file

@ -76,6 +76,15 @@ void correlator_free(correlator_ctx_t *ctx)
ctx->search_sequence_len = 0;
}
void correlator_reset(correlator_ctx_t *ctx)
{
// Clear the history buffer
memset(ctx->input_history, 0, ctx->buffer_size * sizeof(ctx->input_history[0]));
// start writing from the beginning
ctx->history_ptr = 0;
}
float complex correlator_step(correlator_ctx_t *ctx, float complex sample)
{

View file

@ -67,6 +67,16 @@ bool correlator_init(correlator_ctx_t *ctx, const float complex *search_seq, siz
*/
void correlator_free(correlator_ctx_t *ctx);
/*!
* \brief Reset a correlator.
*
* \details
* Erases all data in the history buffer and starts writing from the beginning.
*
* \param ctx The correlator context to reset.
*/
void correlator_reset(correlator_ctx_t *ctx);
/*!
* \brief Process one sample in the correlator.
*

View file

@ -600,6 +600,24 @@ result_t layer1_rx_shutdown(layer1_rx_t *rx)
}
result_t layer1_rx_reset(layer1_rx_t *rx)
{
// reset the state machine
rx->state = RX_STATE_ACQUISITION;
// reset the correlator (to avoid spurious preamble detection)
correlator_reset(&rx->preamble_correlator);
// reset symbol synchronizer
symsync_crcf_reset(rx->symsync);
// drop partial debug info
reset_packet_debug_info(rx);
return OK;
}
bool layer1_rx_is_busy(const layer1_rx_t *rx)
{
return is_squelch_open(rx);

View file

@ -114,7 +114,7 @@ result_t layer1_rx_shutdown(layer1_rx_t *rx);
* \param rx Pointer to the receiver context.
* \param samples Pointer to the samples to process.
* \param sample_count Number of samples to process.
* \returns The result of the shutdown.
* \returns The result of the sample processing.
*/
result_t layer1_rx_process(layer1_rx_t *rx, const float complex *samples, size_t sample_count);
@ -142,4 +142,20 @@ bool layer1_rx_is_busy(const layer1_rx_t *rx);
*/
float layer1_rx_get_coarse_carrier_frequency(const layer1_rx_t *rx);
/*!
* \brief Reset the receiver.
*
* This ensures that the receiver can lock on to newly received packets in a
* defined way. The following submodules are reset:
*
* - Correlator
* - RX state machine
* - Symbol synchronization
*
* \param rx Pointer to the receiver context.
* \returns The result of the reset.
*/
result_t layer1_rx_reset(layer1_rx_t *rx);
#endif // LAYER1_RX_H

View file

@ -317,6 +317,7 @@ int main(int argc, char **argv)
} else if(on_air) { // ret == 0
fprintf(stderr, "TX -> RX\n");
RESULT_CHECK(sdr_flush_tx_buffer(&sdr));
RESULT_CHECK(layer1_rx_reset(&rx));
RESULT_CHECK(sdr_stop_tx(&sdr));
RESULT_CHECK(sdr_start_rx(&sdr));