TSAMPLEOFFSET is a signed number for a relative offset of the sampling instant.
TSAMPLEOFFSET configures when the sample is taken, after an antenna switch has happened. It must be configured before starting the radio. The value should be chosen so that the signal through the receiver chain to the A/D converter has settled after the antenna switch before the sampling occurs. This delay varies for 1 Mbps and 2 Mbps data rates due to different filter settings. It may also depend on external components. The following values are recommended:
| PHY (Mbps) | slotDuration (µs) | TSAMPLEOFFSET |
|---|---|---|
| 1 | 1 | 1 |
| 1 | 2 | 15 |
| 2 | 1 | 6 |
| 2 | 2 | 20 |
The setting for 1Mbps, 1 µs causes the sampling to happen just before the next antenna switch. A signal with severe multipath may not have settled and can affect the quality of the IQ samples. This limitation stems from the bandwidth of the filters in 1 Mbps mode.
The ideal value of TSAMPLEOFFSET may be determined experimentally by sampling at a high rate and visually checking the impact from switching.
