The RF parameters you want to use is close to what is required for WMBUS C mode. Try the following register settings (deviation and frequency have to be changed):
FS_CFG 12
FS_DIG1 0
FS_DIG0 5F
FS_CAL1 40
FS_CAL0 E
FS_DIVTWO 3
FS_DSM0 33
FS_DVC0 17
FS_PFD 50
FS_PRE 6E
FS_REG_DIV_CML 14
FS_SPARE AC
FS_VCO0 B4
XOSC5 E
XOSC1 3
SYNC3 54
SYNC2 3D
SYNC1 54
SYNC0 CD
SYNC_CFG1 C
SYNC_CFG0 17
DEVIATION_M 9A
MODCFG_DEV_E 6
DCFILT_CFG C
PREAMBLE_CFG1 18
PREAMBLE_CFG0 17
FREQ_IF_CFG 0
IQIC C6
CHAN_BW 1
MDMCFG1 46
MDMCFG0 5
DRATE2 A9
DRATE1 99
DRATE0 99
AGC_REF 3C
AGC_CS_THR F6
AGC_GAIN_ADJUST 0
AGC_CFG3 3
AGC_CFG2 20
AGC_CFG1 A9
AGC_CFG0 C0
PA_CFG2 7F
PA_CFG1 56
PA_CFG0 78
IF_MIX_CFG 0
FREQOFF_CFG 20
TOC_CFG B
SOFT_TX_DATA_CFG 0
SETTLING_CFG 3