srsLTE使用LimeSDR代码分析PHY层流程

RF处理线程

lib/src/phy/rf/rf_soapy_imp.c
int rf_soapy_recv_with_time(void *h,
void *data,
uint32_t nsamples,
bool blocking,
time_t *secs,
double *frac_secs)

->

 lib/src/phy/rf/rf_dev.h
int (*srslte_rf_recv_with_time)(void *h, void *data, uint32_t nsamples,
bool blocking, time_t *secs,double *frac_secs)

->

lib/src/radio/radio_multi.cc

bool rx_now(cf_t *buffer[SRSLTE_MAX_PORTS], uint32_t nof_samples, srslte_timestamp_t* rxd_time)

->

srsenb/src/phy/txrx.cc
void run_thread() 接收完成后，触发信号，通知后续线程,也就是后面的发送接收线程。

eNB收发处理线程

srsenb/src/phy/phch_worker.cc
void work_imp();

->

srsenb/src/phy/phch_worker.cc
void srslte_enb_ul_fft(srslte_enb_ul_t *q)

填充关键的srslte_enb_ul_t->sf_symbols，这个指针在 int srslte_ofdm_rx_init(srslte_ofdm_t *q, srslte_cp_t cp_type, cf_t *in_buffer,cf_t *out_buffer,uint32_t max_prb)函数中被赋值，被共享，因此后面会不好理解何时srslte_enb_ul_t->sf_symbols被赋值

另外就是关注 int srslte_enb_ul_init(srslte_enb_ul_t *q,cf_t *in_buffer,uint32_t max_prb)中对于signal_buffer_rx的共享方式，也能解释后面的不需要拷贝内存的操作，主要就是指针被共享了。

srsenb/src/phy/phch_worker.cc
int decode_pucch()

->

lib/src/phy/enb/enb_ul.c
int srslte_enb_ul_get_pucch(srslte_enb_ul_t *q, uint16_t rnti,
uint32_t pdcch_n_cce, uint32_t sf_rx,
srslte_uci_data_t *uci_data)

->

lib/src/phy/enb/enb_ul.c
int get_pucch(srslte_enb_ul_t *q, uint16_t rnti,
uint32_t pdcch_n_cce, uint32_t sf_rx,
srslte_uci_data_t *uci_data, uint8_t bits[SRSLTE_PUCCH_MAX_BITS], uint32_t nof_bits)

->

lib/src/phy/phch/pusch.c
int srslte_pusch_decode(srslte_pusch_t *q,
srslte_pusch_cfg_t *cfg, srslte_softbuffer_rx_t *softbuffer,
cf_t *sf_symbols,
cf_t *ce, float noise_estimate, uint16_t rnti,
uint8_t *data, srslte_cqi_value_t *cqi_value, srslte_uci_data_t *uci_data)

->

lib/src/phy/modem/demod_soft.c
int srslte_demod_soft_demodulate_s(srslte_mod_t modulation, const cf_t* symbols, short* llr, int nsymbols)(QPSK解码）