XDfePrach_DDCCfg - XDfePrach_DDCCfg - 2.0 English

XDfePrach_DDCCfg - XDfePrach_DDCCfg - 2.0 English - PG391

RFSoC DFE PRACH LogiCORE IP Product Guide (PG391)

Document ID

PG391

Release Date

2025-11-26

Version

2.0 English

PRACH Decimation Configuration.

Declaration

typedef struct
{
  u32 DecimationRate;
  u32 UserSCS;
  u32 RachGain[6];
} XDfePrach_DDCCfg;

Table 1. Structure XDfePrach_DDCCfg Member Description
Member	Description
DecimationRate	[0,1,2,3,4,8,9,10,11] Decimation Rate required to go from Fc/16 MS/s to the RACH sample rate: 0: 1x decimation(not allowed when XDfePrach_CarrierCfg.CCRate==0) 1: 2x decimation 2: 4x decimation 3: 8x decimation(not allowed when XDfePrach_CarrierCfg.CCRate==3) 4: 16x decimation(not allowed when XDfePrach_CarrierCfg.CCRate==3 or XDfePrach_CarrierCfg.CCRate==2) 8: 3x decimation 9: 6x decimation 10: 12x decimation(not allowed when XDfePrach_CarrierCfg.CCRate==3) 11: 24x decimation(not allowed when XDfePrach_CarrierCfg.CCRate==3 or XDfePrach_CarrierCfg.CCRate==2) Note: This Field is not used by the API when operating in Dynamic Mode. The Decimation rate is supplied directly from the Decimation field in the Dynamic Control Packet(DCP)
UserSCS	[0-4,12-15] SubCarrier spacing of the RACH channel this DDC is decimating. Required to determine the NCO phase increment: 0: 15KHz spacing 1: 30KHz spacing 2: 60KHz spacing 3: 120KHz spacing 4: 240KHz spacing 12: 1.25KHz spacing 13: 3.75KHz spacing 14: 5KHz spacing 15: 7.5KHz spacing Note: This Field is not used by the API when operating in Dynamic Mode. The Phase increment and Decimation rate are supplied directly to from the FCW field and the Decimation field in the Dynamic Control Packet(DCP) so there is no requirement for the core to know what the RACH SCS is.
RachGain	[0-3] The array of [6] Decimation Gains. Gain is applied to all active Decimation filters. Decimation filters are enabled depending upon the total decimation rate. The gain is applied on a per filter basis: Always applies: CCDecGain[0]=0: Gain of 0dB in last decimating filter CCDecGain[0]=1: Gain of 6dB in last decimating filter CCDecGain[0]=2: Gain of 12dB in last decimating filter CCDecGain[0]=3: Gain of 18dB in last decimating filter Only applies if total_decimation_rate = {4, 8, 16, 32, 6, 12, 24, 48, 96) CCDecGain[1]=0: Gain of 0dB in fifth decimating filter CCDecGain[1]=1: Gain of 6dB in fifth decimating filter Only applies if total_decimation_rate = {8, 16, 32, 12, 24, 48, 96) CCDecGain[2]=0: Gain of 0dB in fourth decimating filter CCDecGain[2]=1: Gain of 6dB in fourth decimating filter Only applies if total_decimation_rate = {16, 32, 24, 48, 96) CCDecGain[3]=0: Gain of 0dB in third decimating filter CCDecGain[3]=1: Gain of 6dB in third decimating filter Only applies if total_decimation_rate = {32, 48, 96) CCDecGain[4]=0: Gain of 0dB in second decimating filter CCDecGain[4]=1: Gain of 6dB in second decimating filter Only applies if total_decimation_rate = {96) CCDecGain[5]=0: Gain of 0dB in first decimating filter CCDecGain[5]=1: Gain of 6dB in first decimating filter