某项目GSM的tuner配置

谁借莪１个温暖的怀抱￠ 2022-10-29 05:21 12阅读 0赞

某项目的天线tuner需要配置如下：  
GSM1800/1900 GPIO-58需要设置为0，RFC连接到RF1，天线匹配RF1上的电容值；  
GSM850/900 GPIO-58需要设置为1，RFC连接到RF2，天线匹配RF2上的电容值。

原理图如下：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nvcm5lcnN0b25lMQ_size_16_color_FFFFFF_t_70]  
按照如下方式修改：

rfc_sig_info_type rf_card_sdr105_riot_cls3_9x05_init_gsm_rx_sig_cfg =
    {
        
      RFC_ENCODED_REVISION,
      {
        
    //begin: stone added for ant switch
    #if defined(RF_T201_TUNER)
    {
         (int)RFC_SDR105_RIOT_CLS3_9X05_TUNER_VC1_GPIO_58, {
         RFC_LOW, 0 }, {
        RFC_LOW, 0 }  },
    #endif
    //end: stone added for ana switch
     
        {
         (int)RFC_SIG_LIST_END,   {
         RFC_LOW, 0 }, {
        RFC_LOW, 0 } }
      },
    };
     
    rfc_sig_info_type rf_card_sdr105_riot_cls3_9x05_init_gsm_tx_sig_cfg =
    {
        
      RFC_ENCODED_REVISION,
      {
        
    //begin: stone added for ant switch
    #if defined(RF_T201_TUNER)
             {
         (int)RFC_SDR105_RIOT_CLS3_9X05_TUNER_VC1_GPIO_58, {
         RFC_LOW, 0 }, {
        RFC_LOW, 0 }  },
    #endif
    //end: stone added for ana switch
     
        {
         (int)RFC_SIG_LIST_END,   {
         RFC_LOW, 0 }, {
        RFC_LOW, 0 } }
      },
    };

在GSM850的sig\_cfg中修改：

rfc_sig_info_type rf_card_sdr105_riot_cls3_9x05_rx0_gsm_g850_sig_cfg =
    {
        
      RFC_ENCODED_REVISION,
      {
        
    //begin: stone added for ana switch
    #ifdef  RF_T201_TUNER
             {
         (int)RFC_SDR105_RIOT_CLS3_9X05_TUNER_VC1_GPIO_58, {
         RFC_HIGH, -10 }, {
        RFC_LOW, 0 }  },
    #endif
    //end: stone added for ana switch
    ……
          {
         (int)RFC_SIG_LIST_END,   {
         RFC_LOW, 0 }, {
        RFC_LOW, 0 } }
      },
    };
    rfc_sig_info_type rf_card_sdr105_riot_cls3_9x05_tx0_gsm_g850_sig_cfg =
    {
        
      RFC_ENCODED_REVISION,
      {
        
    //begin: stone added for ana switch
    #ifdef  RF_T201_TUNER
             {
         (int)RFC_SDR105_RIOT_CLS3_9X05_TUNER_VC1_GPIO_58, {
         RFC_HIGH, -10 }, {
        RFC_LOW, 0 }  },
    #endif
    //end: stone added for ana switch
    ……
        {
         (int)RFC_SIG_LIST_END,   {
         RFC_LOW, 0 }, {
        RFC_LOW, 0 } }
      },
    };

实际测试GSM850连接数据业务时，GPIO-58的波形如下：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nvcm5lcnN0b25lMQ_size_16_color_FFFFFF_t_70 1]  
并不是预期一直为高。

如果在GSM850的rx和tx sig\_cfg中改为  
\{ (int)RFC\_SDR105\_RIOT\_CLS3\_9X05\_TUNER\_VC1\_GPIO\_58, \{ RFC\_HIGH, -10 \}, \{ RFC\_HIGH, 0 \} \},  
在GSM1800中改为  
\{ (int)RFC\_SDR105\_RIOT\_CLS3\_9X05\_TUNER\_VC1\_GPIO\_58, \{ RFC\_LOW, -10 \}, \{ RFC\_LOW, 0 \} \},  
测试GSM850是一直为高，但是在GSM1800时的波形不能完全为低，如图所示：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nvcm5lcnN0b25lMQ_size_16_color_FFFFFF_t_70 2]  
占空比约为1/8，如果设为4上1下，占空比约为1/16。（用万用表测量到的是有效值0.5V左右，要用示波器抓才能看的清楚）  
高通的解释：

> > let us assume that we have a Tx burst in the 1st slot. So as soon as the Tx operation is called for , the RFC structures for GSM850 Tx operation will be called .  
> > rf\_card\_sdr105\_riot\_cls3\_9x05\_tx0\_gsm\_g850\_sig\_cfg will be called at the time of Tx slot.  
> > After entering the structure we will set the GRFC to HIGH for the Tx operation.  
> > As soon as the Tx operation completes the GRFC is brought back to LOW state .  
> > Since now the next Tx slot will be after 8 GSM slots , the GRFC status will be LOW only .  
> > As soon as the next slot comes , the GRFC will be HIGH.

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