请问deviation的频偏是根据什么来确定设置？

频偏会影响调频波的带宽，根据公式Rx BW > 2 * Deviation + 4 * Freq. Error，另外对灵敏度也有影响

Freq. Error这个参数是什么意思，怎么知道

Measure the actual frequency on a spectrum analyzer and the delta from the expected frequency gives the frequency error.

Eg: if the measured frequency is 2437.3225 Mhz then the frequency error = 2437.3225 – 2437.3125 = 0.01Mhz (10 Khz). For accurate measurement set a low span in the spectrum analyzer , like 100Khz and RBW of 100Hz.

To convert this to ppm -> (Freq error/expected frequency) * 10^6 -> (0.01/2437.3125) * 10^6 = 4.1 ppm.

您好，想向您请教一个频偏的问题：频谱仪测试CC2640的0信道单载波，频率偏低50KHz,然后如下程序，在发射一个单载波的情况下，无论我这么调整信道和SET_CCFG_MODE_CONF_XOSC_CAPARRAY_DELTA的值，信道可以在0-39切换，但是每次都偏低50KHz,即不能通过调整内部晶振来调整频偏，请问可能的原因和解决方法是？

C:tisimplelinkble_sdk_2_02_01_18examplescc2650emsimple_peripheral

static void SimpleBLEPeripheral_init(void)
[
···
HCI_EXT_SetTxPowerCmd(HCI_EXT_TX_POWER_5_DBM);                 //TX功率5dBm
HCI_EXT_ModemTestTxCmd(LL_EXT_TX_UNMODULATED_CARRIER,11);       // TX，非调制，0信道
···



C:titirtos_cc13xx_cc26xx_2_20_01_08productscc26xxware_2_24_02_17393startup_files
#ifndef SET_CCFG_MODE_CONF_XOSC_CAP_MOD

#define SET_CCFG_MODE_CONF_XOSC_CAP_MOD              0x0        // Apply cap-array delta
// #define SET_CCFG_MODE_CONF_XOSC_CAP_MOD                 0x1        // Don't apply cap-array delta
#endif

#ifndef SET_CCFG_MODE_CONF_XOSC_CAPARRAY_DELTA
#define SET_CCFG_MODE_CONF_XOSC_CAPARRAY_DELTA          0x06       // Signed 8-bit value, directly modifying trimmed XOSC cap-array value
#endif