UE YAML Reference

How to use this page

UE reads UE.yaml from its current working directory at startup. Copy a config/UE_*.yaml preset that matches your hardware and scenario, then edit the copy. Configuration is not hot-reloaded; restart the UE after making changes.

The tables follow the top-level YAML structure and use full paths such as uplink.arq_enabled to distinguish similarly named fields. A typical value is guidance, not a guaranteed default for every preset. If an optional section is omitted, the parser supplies its default values.

Keep coupled frame-structure, duplex, frequency, and resource-mapping fields consistent with the BS configuration.

Parameter tables

radio

Path	Type/Unit	Typical Value	Description
radio.radio_backend	string	uhd	Radio I/O backend. Use uhd for real USRPs or sim for the channel simulator.

simulation

Path	Type/Unit	Typical Value	Description
simulation.session	string	oisac_sim	Shared simulator session namespace.
simulation.enable_comm_rx	bool	true	Simulator produces the communication RX path.
simulation.enable_sensing_rx	bool	true	Simulator produces sensing RX paths.
simulation.enable_uplink	bool	false	Simulator routes the UE-to-BS uplink stream.
simulation.pacing_enabled	bool	true	Pace simulator output to wall-clock sample time.
simulation.noise_power_dbfs	float / dBFS	-100	AWGN power per RX channel.
simulation.snr_control_enable	bool	false	Maintain target_snr_db by scaling clean simulated signal.
simulation.target_snr_db	float / dB	40	Initial target SNR when SNR control is enabled.
simulation.control_port	int	10002	ChannelSimulator control port.
simulation.cfo_hz	float / Hz	0	Initial BS-to-UE CFO before UE RX correction. The initial UE-to-BS CFO has the opposite sign, is carrier-ratio-scaled in FDD, and its residual then follows UE uplink TX retuning.
simulation.sample_rate_offset_ppm	float / ppm	0	UE sample-clock offset relative to BS.
simulation.timing_offset_samples	int / samples	0	Constant integer sample delay.
simulation.array_spacing_m	float / m	0.04283	Physical ULA spacing.
simulation.array_spacing_lambda	float	0.5	Legacy ULA spacing in wavelengths.
simulation.ring_capacity_samples	int	262144	Shared-memory ring capacity.
simulation.steering_override_file	string	""	Optional array-manifold matrix file. When empty, the simulator generates a ULA manifold from angle_deg. When set, angle_deg no longer affects the array response; encode the angle-dependent amplitude and phase directly in the matrix.
simulation.comm_multipath_taps[]	object[]	optional	Communication taps with delay_samples, gain_db, and phase_deg.
simulation.targets[]	object[]	optional	Monostatic point scatterers.
simulation.bistatic_targets[]	object[]	optional	Bistatic/communication point scatterers.

rf_sampling

Path	Type/Unit	Typical Value	Description
rf_sampling.sample_rate	float / Hz	50000000	Baseband sample rate.
rf_sampling.bandwidth	float / Hz	50000000	Analog bandwidth.
rf_sampling.rx_gain	float / dB	10	UE downlink RX gain.
rf_sampling.rx_agc_enable	bool	true	Enable UE downlink hardware RX AGC.
rf_sampling.rx_agc_low_threshold_db	float / dB	14	Increase RX gain below this filtered delay-spectrum threshold.
rf_sampling.rx_agc_high_threshold_db	float / dB	16	Decrease RX gain above this threshold.
rf_sampling.rx_agc_max_step_db	float / dB	1	Maximum RX gain step per AGC update.
rf_sampling.rx_agc_update_frames	int	4	Minimum processed-frame interval between AGC updates.

usrp_device

Path	Type/Unit	Typical Value	Description
usrp_device.device_args	string	addr=...	USRP device args.
usrp_device.clock_source	string	external	UE clock source: internal, external, or gpsdo.

ofdm_frame

Path	Type/Unit	Typical Value	Description
ofdm_frame.fft_size	int	1024	OFDM FFT size.
ofdm_frame.cp_length	int / samples	128	Cyclic prefix length.
ofdm_frame.sync_pos	int	1	Sync symbol index.
ofdm_frame.enable_sec_sync_symbol	bool	false	Expect a duplicate ZC sync symbol at sync_pos-1.
ofdm_frame.enable_cfo_training_sequence	bool	false	Use the sync_pos+1 CFO training field to resolve CFO aliases.
ofdm_frame.cfo_training_period_samples	int / samples	16	CFO training repetition period.
ofdm_frame.num_symbols	int	100	OFDM symbols per frame.
ofdm_frame.sensing_symbol_num	int	100	Symbols used for sensing.
ofdm_frame.frame_queue_size	int	32	Demodulated RX frame queue capacity.
ofdm_frame.zc_root	int	29	Zadoff-Chu root.
ofdm_frame.pilot_positions	int[]	[571,...]	Comb-pilot subcarrier indices.
ofdm_frame.midframe_pilot_symbols	int[]	[]	Optional mid-frame BPSK pilot symbols.
ofdm_frame.midframe_pilot_seed	int	1296453708	Deterministic mid-frame BPSK pilot seed.

cuda

Path	Type/Unit	Typical Value	Description
cuda.cuda_demod_pipeline_slots	int	3	CUDA demodulation pipeline slots.
cuda.cuda_ldpc_decoder_backend	string	gpu	CUDA demod LDPC decoder backend: gpu or cpu.
cuda.cuda_ldpc_worker_buffers	int	3	CUDA LDPC async worker batch buffers.
cuda.cuda_ldpc_cross_frame_flush_frames	int	2	Max frames accumulated before CUDA LDPC batch decode.
cuda.cuda_ldpc_cross_frame_flush_us	float / us	1000	Max CUDA LDPC cross-frame batch wait time.

ldpc

Path	Type/Unit	Typical Value	Description
ldpc.fixed_point	bool	false	Use int16/Q16 CPU LDPC decode path.
ldpc.fixed_point_scale	int	16	LLR scale before int16 saturation.

downlink

Path	Type/Unit	Typical Value	Description
downlink.center_freq	float / Hz	2400000000	UE downlink RF center frequency.
downlink.rx_wire_format	string	sc16	UE downlink RX wire format.
downlink.rx_channel	int	0	UE downlink RX channel index.
downlink.equalizer_mode	string	mmse	Downlink equalizer inverse mode: zf or mmse.
downlink.channel_tracking_mode	string	pilot_phase	Per-symbol comb-pilot tracking mode.
downlink.equalizer_mag_floor	float	1e-6	Lower bound for `
downlink.channel_tracking_min_pilot_snr	float	1e-4	Minimum comb-pilot residual weight before fallback.
downlink.arq_enabled	bool	false	Enable downlink ARQ on the UE receiver.
downlink.arq_ordered_delivery	bool	false	Buffer downlink packets for in-order UDP delivery.
downlink.arq_window_packets	int	256	Downlink ARQ receive/reorder window; valid range 1–32767.
downlink.arq_feedback_interval_ms	int / ms	10	Minimum interval between downlink ARQ ACK feedback packets.

uplink

Path	Type/Unit	Typical Value	Description
uplink.enabled	bool	false	Master switch for UE uplink/duplex.
uplink.duplex_mode	string	tdd	Must match BS: tdd windowed uplink or fdd full-frame uplink.
uplink.center_freq	float / Hz	2500000000	FDD-only uplink carrier. TDD uses the downlink center frequency.
uplink.idle_waveform	string	random_qpsk	UE uplink idle waveform: random_qpsk or zero.
uplink.symbol_start	int	90	TDD-only first uplink symbol.
uplink.symbol_count	int	10	TDD-only uplink window length.
uplink.guard_symbols	int	1	TDD-only leading guard symbols.
uplink.tx_gain	float / dB	0	UE uplink TX gain.
uplink.tx_channel	int	0	UE uplink TX channel index.
uplink.wire_format_tx	string	sc16	UE uplink TX wire format.
uplink.ue_timing_advance	int / samples	50	UE uplink transmit timing advance.
uplink.debug_self_channel	bool	false	Estimate UE self-TX leakage channel from RX windows for TADV debugging.
uplink.ertm_to_enable	bool	false	Enable eRTM TO payload consumption and TO logs.
uplink.ertm_timing_metric	string	delay_magnitude	Differential-TO metric: phase-robust delay_magnitude or coherent maximum_likelihood.
uplink.ertm_delay_oversample_factor	int	10	eRTM delay-spectrum IFFT oversampling factor.
uplink.ertm_dl_rf_delay_samples	float / samples	67.0	Calibrated downlink RF-chain delay for eRTM equations.
uplink.ertm_ul_rf_delay_samples	float / samples	67.0	Calibrated uplink RF-chain delay for eRTM equations.
uplink.ertm_debug_output_enabled	bool	false	Enable UE-side eRTM debug ZMQ spectra.
uplink.ertm_report_interval_frames	int / frames	32	BS eRTM report cadence; keep matched with BS.
uplink.arq_enabled	bool	false	Enable uplink ARQ on the UE transmitter.
uplink.arq_window_packets	int	256	Uplink ARQ outstanding packet window; valid range 1–32767.
uplink.arq_retransmit_timeout_ms	int / ms	100	Uplink ARQ retransmission timeout.
uplink.arq_max_retries	int	5	Max uplink retransmission retries; 0 means unlimited within the window.

sync_tracking

Path	Type/Unit	Typical Value	Description
sync_tracking.sync_queue_size	int	32	Sync-search batch queue capacity.
sync_tracking.sync_cfo_alias_search_range_hz	float / Hz	800000	CFO range covered by the sync alias resolver.
sync_tracking.reset_hold_s	float / s	0.5	Invalid-delay duration before a hard reset to sync search.
sync_tracking.software_sync	bool	true	Enable software sync tracking.
sync_tracking.predictive_delay	bool	true	Use CFO-based predictive delay compensation.
sync_tracking.hardware_sync	bool	false	Enable hardware synchronization mode.
sync_tracking.hardware_sync_tty	string	/dev/ttyUSB0	Serial device for the hardware sync controller.
sync_tracking.ocxo_pi_kp_fast	float	30	Fast-stage OCXO PI proportional gain.
sync_tracking.ocxo_pi_ki_fast	float	1	Fast-stage OCXO PI integral gain.
sync_tracking.ocxo_pi_kp_slow	float	30	Slow-stage OCXO PI proportional gain.
sync_tracking.ocxo_pi_ki_slow	float	0.05	Slow-stage OCXO PI integral gain.
sync_tracking.ocxo_pi_switch_abs_error_ppm	float / ppm	0.0002	Error threshold for switching to slow OCXO PI stage.
sync_tracking.ocxo_pi_switch_hold_s	float / s	60	Hold time below threshold before switching stages.
sync_tracking.ocxo_pi_max_step_fast_ppm	float / ppm	0.01	Fast-stage maximum OCXO adjustment per update.
sync_tracking.ocxo_pi_max_step_slow_ppm	float / ppm	0.01	Slow-stage maximum OCXO adjustment per update.
sync_tracking.ocxo_pi_max_step_ppm	float / ppm	optional	Legacy alias applied to both fast and slow max-step fields.
sync_tracking.akf_enable	bool	true	Enable adaptive Kalman filter on hardware-sync error_ppm.
sync_tracking.akf_bootstrap_frames	int	64	Cold-start frames before normal AKF updates.
sync_tracking.akf_innovation_window	int	64	Innovation history window for adaptation.
sync_tracking.akf_max_lag	int	4	Maximum innovation autocorrelation lag.
sync_tracking.akf_adapt_interval	int	64	Frame interval for adaptive Q/R updates.
sync_tracking.akf_gate_sigma	float	3	Innovation gate in sigma units.
sync_tracking.akf_tikhonov_lambda	float	1e-3	Tikhonov regularization for LS adaptation.
sync_tracking.akf_update_smooth	float	0.2	Exponential smoothing for updated Q/R.
sync_tracking.akf_q_wf_min	float	1e-10	White-frequency-noise lower bound.
sync_tracking.akf_q_wf_max	float	1e2	White-frequency-noise upper bound.
sync_tracking.akf_q_rw_min	float	1e-12	Random-walk-frequency-noise lower bound.
sync_tracking.akf_q_rw_max	float	1e1	Random-walk-frequency-noise upper bound.
sync_tracking.akf_r_min	float	1e-8	Observation-noise variance lower bound.
sync_tracking.akf_r_max	float	1e3	Observation-noise variance upper bound.
sync_tracking.desired_peak_pos	int	20	Target delay-peak position for alignment logic.

sensing

Path	Type/Unit	Typical Value	Description
sensing.sensing_delay_correction_mode	string	los_tracking	Bistatic sensing delay correction source: los_tracking or ertm_absolute.
sensing.bi_enabled	bool	true	Enable bistatic sensing processing.
sensing.range_fft_size	int	1024	Range FFT size.
sensing.doppler_fft_size	int	100	Doppler FFT size.
sensing.view_range_bins	int	0	Backend RD view width; 0 means full range.
sensing.view_doppler_bins	int	0	Backend RD view height; 0 means full Doppler size.
sensing.output_mode	string	dense	dense full-buffer output or compact_mask selected-RE output.
sensing.on_wire_format	string	complex_float32	Sensing payload wire format.
sensing.backend_processing_enabled	bool	false	Publish backend RD/CFAR/micro-Doppler sidecars when supported.
sensing.symbol_stride	int	20	Default dense-mode STRD applied at startup.

resource_preview

Path	Type/Unit	Typical Value	Description
resource_preview.data_resource_blocks[]	object[]	optional	Payload / sensing-pilot RE rectangles; each item has kind, symbol_start, symbol_count, subcarrier_start, and subcarrier_count.
resource_preview.mask_blocks[]	object[]	optional	Compact sensing RE rectangles with symbol_start, symbol_count, subcarrier_start, and subcarrier_count.

measurement

Path	Type/Unit	Typical Value	Description
measurement.measurement_enable	bool	false	Enable internal PRBS measurement checking.
measurement.measurement_mode	string	internal_prbs	Measurement checker mode.
measurement.measurement_run_id	string	""	Run ID written to measurement CSV summaries.
measurement.measurement_output_dir	string	""	Output directory for measurement CSV summaries.
measurement.measurement_payload_bytes	int / bytes	1024	Expected bytes per measurement payload.
measurement.measurement_prbs_seed	int	0x5A	Base seed for rebuilding deterministic PRBS payloads.
measurement.measurement_packets_per_point	int	1	Expected packets for one measurement epoch.
measurement.measurement_max_packets_per_frame	int	1	Max measurement packets checked per frame; 0 means unlimited.

network_output

Path	Type/Unit	Typical Value	Description
network_output.udp_input_ip	string / IPv4	0.0.0.0	UE uplink payload UDP bind IP.
network_output.udp_input_port	int	50002	UE uplink payload UDP bind port.
network_output.udp_output_ip	string / IPv4	""	UE decoded downlink UDP destination IP; empty uses runtime.default_out_ip.
network_output.udp_output_port	int	50001	UE decoded downlink UDP destination port.
network_output.udp_egress_pacer_enabled	bool	false	Enable queued pacing for decoded UDP egress.
network_output.udp_egress_pacer_target_mbps	float / Mbps	0	Egress pacer target rate; 0 auto-estimates.
network_output.udp_egress_pacer_queue_packets	int	10240	Egress pacer queue capacity.
network_output.udp_egress_pacer_max_delay_ms	float / ms	0	Max queued packet age; 0 disables age drops.
network_output.bi_sensing_output_enabled	bool	true	Enable bistatic sensing ZMQ output.
network_output.bi_sensing_ip	string / IPv4	0.0.0.0	Bistatic sensing/control ZMQ bind IP.
network_output.bi_sensing_port	int	8889	Bistatic sensing PUB port.
network_output.channel_ip	string / IPv4	0.0.0.0	Channel-estimate PUB IP.
network_output.channel_port	int	12348	Channel-estimate PUB port.
network_output.pdf_ip	string / IPv4	0.0.0.0	Delay-spectrum PUB IP.
network_output.pdf_port	int	12349	Delay-spectrum PUB port.
network_output.constellation_ip	string / IPv4	0.0.0.0	Constellation PUB IP.
network_output.constellation_port	int	12346	Constellation PUB port.
network_output.self_channel_ip	string / IPv4	0.0.0.0	UE self-channel debug PUB IP.
network_output.self_channel_port	int	12350	UE self-channel debug PUB port.
network_output.self_pdf_ip	string / IPv4	0.0.0.0	UE self-delay-spectrum debug PUB IP.
network_output.self_pdf_port	int	12351	UE self-delay-spectrum debug PUB port.
network_output.ertm_debug_ip	string / IPv4	0.0.0.0	UE eRTM debug PUB IP.
network_output.ertm_debug_port	int	12362	UE eRTM debug PUB port.
network_output.control_port	int	10001	ZMQ ROUTER port for runtime control.

cpu_cores

Path	Type/Unit	Typical Value	Description
cpu_cores.downlink_cpu_cores	int[]	[1,2,3]	UE downlink cores: RX, processing, bit processing.
cpu_cores.demod_worker_cpu_cores	int[]	[]	UE CPU demod worker cores; empty starts one unbound worker.
cpu_cores.ldpc_worker_cpu_cores	int[]	[]	UE CPU LDPC decode worker cores; empty starts one unbound worker.
cpu_cores.sensing_cpu_cores	int[]	[4]	UE bistatic sensing cores.
cpu_cores.uplink_cpu_cores	int[]	[]	UE uplink cores: LDPC encode, modulation, TX send, UDP receive.
cpu_cores.main_cpu_core	int	-1	Main-thread CPU core; -1 disables binding.

runtime

Path	Type/Unit	Typical Value	Description
runtime.default_out_ip	string / IPv4	127.0.0.1	Default destination IP for UDP and VOFA+ outputs when specific IP fields are empty.
runtime.vofa_debug_ip	string / IPv4	""	VOFA+ debug destination IP; empty uses default_out_ip.
runtime.vofa_debug_port	int	12347	VOFA+ debug destination port.

logging

Same hierarchical filter as BS (logging.*). Debug examples: ertm: debug, recovery: info, demod.snr: info. Performance (paths end with _profiling, off until set): demod_profiling: info, demod_eq_profiling: info.

Resource-map notes:

• resource_preview.data_resource_blocks should normally match between BS and UE, including kind.
• Built-in ZC sync symbols, the optional CFO training field, comb pilots, and mid-frame BPSK pilots take precedence over configured resource blocks.
• resource_preview.mask_blocks controls compact sensing export only. In output_mode=compact_mask, runtime STRD is ignored because the mask defines the sampling pattern.
• Compact sensing payloads begin with CompactSensingFrameHeader, followed by fixed-order raw complex<float> samples.