我使用两种不同的数据包格式以21K 的符号速率在 CC1200与 RBW 26KHz 之间进行通信。
格式 A 传输一个字节的前导码以仅用于稳定、同步字= 2字节。 接收器不选通前导码、仅查找同步。 其中 RBW >=位速率。 PER 是无误差的、在0dBm 至-105dbm 的 RF 输入电平下基本相同、但在-55dbm 以上的 RF 输入下、RSSI 水平读取不正确。 它们被限制在大约-55dbm。
格式 B 传输30字节的前导码。 接收器通过 cc1200 GPIO/MCU (不是 cc1200内部)实现前导码、同步字= 4字节。 前导码检测在-55dbm 至阈值范围内是可靠的、但在高于约-50dbm 的射频输入电平时是间歇性的。 正确的前导码检测对于此系统中从0dBm 到阈值的活动通道检测和前导码门控至关重要。 在所有信号级别、预加载 FS 校准的前导码检测时间以及 SRX 后需要~1.155ms、这比 SWRA428A 的 Excel 电子表格上计算出的时间长99us。
在实现 RX_CONFIG_LIMIT = 1时、我首先使用了用户指南和 Siri 中的信息(请参阅下文中的 Siri)、 然后进行了测试和修改以获得更好的结果、但我无法找到允许从~0dBm 到 RX 阈值的正确 RSSI 报告和前导码检测的设置组合。
"您可以使用 RX_CONFIG_LIMIT = 1、但请记住、AGC_CFG1.AGC_WIN_SIZE 应递增1、且通过 AGC_CFG1.AGC_SETTLE_WAIT 编程的 AGC 增益调整之间的等待时间应加倍(与 RX_CONFIG_LIMIT = 0时 SmartRF Studio 建议的值相比)
AGC_SETTLE_WAIT 将影响 T1、这也会影响 PQT 响应时间
PQT 响应时间= T0 + T1
PQT 响应时间是从进入 RX 模式到 PQT_VALID 有效生效所花费的时间(无线电计算出是否在空气中带有前导码所花费的时间)。
我的问题如下：
1.关于格式 A (2字节同步、无前导码门控)、是否有寄存器设置可允许完整范围 RSSI 报告而不影响 RX 灵敏度/BER？
2.关于格式 B (4字节同步、带前导码门控)、是否有寄存器设置可允许全范围前导码/位检测而不影响 RX 灵敏度/BER 或 RSSI 报告？
3.前导码检测速度慢的原因可能是什么?
Below are the base register settings:
{CC1200_IOCFG3, 0x06},
{CC1200_IOCFG2, 0x0B},
{CC1200_IOCFG1, 0x30},
{CC1200_IOCFG0, 0x06},
{CC1200_SYNC3, 0x93},
{CC1200_SYNC2, 0x0B},
{CC1200_SYNC1, 0x51},
{CC1200_SYNC0, 0xDE},
{CC1200_SYNC_CFG1, 0x4A},
{CC1200_SYNC_CFG0, 0x13},
{CC1200_DEVIATION_M, 0xD7},
{CC1200_MODCFG_DEV_E, 0x01},
{CC1200_DCFILT_CFG, 0x5D},
{CC1200_PREAMBLE_CFG1, 0x10},
{CC1200_PREAMBLE_CFG0, 0x8A},
{CC1200_IQIC, 0xCB},
{CC1200_CHAN_BW, 0x90},
{CC1200_MDMCFG1, 0x40},
{CC1200_MDMCFG0, 0x05},
{CC1200_SYMBOL_RATE2, 0x81},
{CC1200_SYMBOL_RATE1, 0x34},
{CC1200_SYMBOL_RATE0, 0x05},
{CC1200_AGC_REF, 0x33},
{CC1200_AGC_CS_THR, 0xEC},
{CC1200_AGC_GAIN_ADJUST, 0x00},
{CC1200_AGC_CFG3, 0xB1},
{CC1200_AGC_CFG2, 0x20},
{CC1200_AGC_CFG1, 0x65},
{CC1200_AGC_CFG0, 0x8F},
{CC1200_FIFO_CFG, 0x00},
{CC1200_DEV_ADDR, 0x00},
{CC1200_SETTLING_CFG, 0x03},
{CC1200_FS_CFG, 0x12},
{CC1200_WOR_CFG1, 0x08},
{CC1200_WOR_CFG0, 0x21},
{CC1200_WOR_EVENT0_MSB, 0x00},
{CC1200_WOR_EVENT0_LSB, 0x00},
{CC1200_RXDCM_TIME, 0x00},
{CC1200_PKT_CFG2, 0x00},
{CC1200_PKT_CFG1, 0x41},
{CC1200_PKT_CFG0, 0x00},
{CC1200_RFEND_CFG1, 0x0F},
{CC1200_RFEND_CFG0, 0x00},
{CC1200_PA_CFG1, 0x5F},
{CC1200_PA_CFG0, 0x54},
{CC1200_ASK_CFG, 0x0F},
{CC1200_PKT_LEN, 0x1E},
{CC1200_IF_MIX_CFG, 0x1C},
{CC1200_FREQOFF_CFG, 0x00},
{CC1200_TOC_CFG, 0x0B},
{CC1200_MARC_SPARE, 0x00},
{CC1200_ECG_CFG, 0x00},
{CC1200_MDMCFG2, 0x08},
{CC1200_EXT_CTRL, 0x01},
{CC1200_RCCAL_FINE, 0x00},
{CC1200_RCCAL_COARSE, 0x00},
{CC1200_RCCAL_OFFSET, 0x00},
{CC1200_FREQOFF1, 0x00},
{CC1200_FREQOFF0, 0x00},
{CC1200_FREQ2, 0x5B},
{CC1200_FREQ1, 0x80},
{CC1200_FREQ0, 0x00},
{CC1200_IF_ADC2, 0x02},
{CC1200_IF_ADC1, 0xEE},
{CC1200_IF_ADC0, 0x10},
{CC1200_FS_DIG1, 0x07},
{CC1200_FS_DIG0, 0xAF},
{CC1200_FS_CAL3, 0x00},
{CC1200_FS_CAL2, 0x20},
{CC1200_FS_CAL1, 0x40},
{CC1200_FS_CAL0, 0x0E},
{CC1200_FS_CHP, 0x28},
{CC1200_FS_DIVTWO, 0x03},
{CC1200_FS_DSM1, 0x00},
{CC1200_FS_DSM0, 0x33},
{CC1200_FS_DVC1, 0xFF},
{CC1200_FS_DVC0, 0x17},
{CC1200_FS_LBI, 0x00},
{CC1200_FS_PFD, 0x00},
{CC1200_FS_PRE, 0x6E},
{CC1200_FS_REG_DIV_CML, 0x1C},
{CC1200_FS_SPARE, 0xAC},
{CC1200_FS_VCO4, 0x14},
{CC1200_FS_VCO3, 0x00},
{CC1200_FS_VCO2, 0x00},
{CC1200_FS_VCO1, 0x00},
{CC1200_FS_VCO0, 0xB5},
{CC1200_SERIAL_STATUS, 0x00},
Format A TX:
{CC1200_PREAMBLE_CFG1, 0x08},
{CC1200_PREAMBLE_CFG0, 0x0A},
{CC1200_DEVIATION_M, 0x6F},
{CC1200_SYNC_CFG1, 0x4A},
{CC1200_PKT_LEN, 67},
{CC1200_IOCFG2, 0x65},
{CC1200_IOCFG0, 0x66},
{CC1200_PKT_CFG0, 0x00},
Format A RX:
{CC1200_PREAMBLE_CFG1, 0x08},
{CC1200_PREAMBLE_CFG0, 0x8B},
{CC1200_DEVIATION_M, 0xD7},
{CC1200_SYNC_CFG1, 0x4A},
{CC1200_PKT_LEN, 67},
{CC1200_IOCFG2, 0x0B},
{CC1200_IOCFG0, 0x06},
{CC1200_AGC_CFG3, 0xB1},
{CC1200_AGC_CFG1, 0x5B},
{CC1200_AGC_CFG0, 0x87},
{CC1200_PKT_CFG0, 0x00},
Format B TX:
{CC1200_PREAMBLE_CFG1, 0x34},
{CC1200_PREAMBLE_CFG0, 0x8A},
{CC1200_DEVIATION_M, 0x6F},
{CC1200_SYNC_CFG1, 0xAA},
{CC1200_PKT_LEN, 20},
{CC1200_IOCFG2, 0x65},
{CC1200_IOCFG0, 0x66},
{CC1200_PKT_CFG0, 0x0C},
Format B RX:
{CC1200_PREAMBLE_CFG1, 0x30},
{CC1200_PREAMBLE_CFG0, 0x8B},
{CC1200_DEVIATION_M, 0xD7},
{CC1200_SYNC_CFG1, 0xAA},
{CC1200_PKT_LEN, 20},
{CC1200_IOCFG2, 0x0B},
{CC1200_IOCFG0, 0x06},
{CC1200_AGC_CFG3, 0xB1},
{CC1200_AGC_CFG1, 0x5B},
{CC1200_AGC_CFG0, 0x87},
{CC1200_PKT_CFG0, 0x0C},