RB Auto Detect Mode (LTE)

Default: Power Based

The RB Auto Detect Mode parameter configures the level of autodetection that the LTE Long Term Evolution demodulator uses. This parameter is available only when the RB Auto Detect parameter is selected.

The PDSCH Bits parameter is only available when RB Auto Detect Mode is set to Decode PDCCH.

For downlink signals, auto detection supports only PDSCH Physical Downlink Shared Channel allocations transmitted on C-RS Cell-specific RS antenna ports.

There are two levels of autodetection, described as follows:

Power Based - Use Power Det. Threshold to set the threshold for power-based detection.
- For downlink, user allocations are detected using codeword power levels and MIMO Multiple Input, Multiple Output: A physical layer (PHY) configuration in which both transmitter and receiver use multiple antennas. parameters specified in the LTE Allocation Editor.
  
  PDSCH detected allocations are grouped according to modulation type (QPSK Quadrature phase shift keying, 16QAM, or 64QAM).
  
  The Precoding type is not autodetected and needs to be specified. When SpMux is selected as the precoding type, No. Layers, No. Codewords, CDD, and Codebook Idx must also be specified, and these parameters are assumed to apply to all autodetected PDSCH allocations.
  
  See Downlink user allocations for more information about configuring autodetection.
- For uplink, once required Channel Parameters are specified for PUSCH, PUCCH, and SRS the demodulator can perform autodetection. PRACH analysis is done separately.
  
  PUSCH Physical Uplink Shared Channel detected allocations are grouped according to modulation type (QPSK, 16QAM, or 64QAM).
  
  See Uplink user allocations for more information about configuring autodetection.
Decoded PDCCH (downlink) - User allocations are determined by decoding PDCCH Physical Downlink Control Channel. See the Downlink user allocations topic for more information on configuring autodetection.

The Decoded PDCCH selection is only available when analyzing downlink signals.

For both Power Based and Decoded PDCCH modes, the demodulator can be configured to autodetect codeword power levels by selecting Auto-detect Power Levels. When codeword power levels are not autodetected, they must be specified using the CW0/1 Power or EPRE parameters in the LTE Allocation Editor for each user allocation. For Decode PDCCH mode, the Expected Num. of Users parameter determines how many user allocations are shown in the LTE Allocation Editor.