CYW43455 Wi-Fi and Bluetooth coexistence in 2.4 GHz with a shared antenna configuration

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KOK_4840576
Level 2
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First solution authored 10 questions asked 5 replies posted

We are using Murata 1MW module having  Infineon IC CYW43455 in a single shared antenna configuration. We are facing packet drops in Bluetooth audio when we try to simultaneously operate 2.4 GHz Wi-Fi and Bluetooth. No problem with 5GHZ Wi-Fi and Bluetooth simultaneous operation.

1. Is this behavior expected  in simultaneous 2.4 GHz Wi-Fi and BT operation ? 

2. How 5GHz was able to share the antenna with Bluetooth simultaneously (TDMA)?  Since only single antenna is used does it switches in time and appear to be simultaneous?   Will the throughput reduce in such case? 

3. Is simultaneous Tx-Tx and Rx-Rx possible?

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Zhengbao_Zhang
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250 sign-ins First comment on KBA 10 questions asked

Hello:

1. Is this behavior expected  in simultaneous 2.4 GHz Wi-Fi and BT operation ? 

A:   Yes, we have different modes since some project needs small bandwidth on BT, but need a stable and larger bandwidth on Wifi. So we defined different modes to help with the cases,  if you want to use A2DP more, I suggest the below params that can be added to the NVRAM.

btc_mode=1

btc_params8=0x4e20

btc_params1=0x7530

btc_params50=0x972c

The parameters are complicated and need fine-tuning according to different requests.

but it is better to co-work with our local support team with real projects.

2. How 5GHz was able to share the antenna with Bluetooth simultaneously (TDMA)?  Since only single antenna is used does it switches in time and appear to be simultaneous?   Will the throughput reduce in such case? 

A:  We have RF controls pins connected to the Diplexer of FEM, the RF control will work well with the firmware provided to the customers, and I think it is TDM mechanism according to the tasks of different priorities on 2.4G. If you want BT more, wifi throughput will decrease, but we can fine-tune it to a good balance. 5G part has a standalone path of the MAC-PA-FEM-Antenna, so the coex will not influence it.

Since only single antenna is used does it switches in time and appear to be simultaneous?

This is true.

3. Is simultaneous Tx-Tx and Rx-Rx possible?

 A:  yes, Tx-Tx, Rx-Rx is possible. many use cases have the same request.

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Zhengbao_Zhang
Moderator
Moderator
Moderator
250 sign-ins First comment on KBA 10 questions asked

Hello:

1. Is this behavior expected  in simultaneous 2.4 GHz Wi-Fi and BT operation ? 

A:   Yes, we have different modes since some project needs small bandwidth on BT, but need a stable and larger bandwidth on Wifi. So we defined different modes to help with the cases,  if you want to use A2DP more, I suggest the below params that can be added to the NVRAM.

btc_mode=1

btc_params8=0x4e20

btc_params1=0x7530

btc_params50=0x972c

The parameters are complicated and need fine-tuning according to different requests.

but it is better to co-work with our local support team with real projects.

2. How 5GHz was able to share the antenna with Bluetooth simultaneously (TDMA)?  Since only single antenna is used does it switches in time and appear to be simultaneous?   Will the throughput reduce in such case? 

A:  We have RF controls pins connected to the Diplexer of FEM, the RF control will work well with the firmware provided to the customers, and I think it is TDM mechanism according to the tasks of different priorities on 2.4G. If you want BT more, wifi throughput will decrease, but we can fine-tune it to a good balance. 5G part has a standalone path of the MAC-PA-FEM-Antenna, so the coex will not influence it.

Since only single antenna is used does it switches in time and appear to be simultaneous?

This is true.

3. Is simultaneous Tx-Tx and Rx-Rx possible?

 A:  yes, Tx-Tx, Rx-Rx is possible. many use cases have the same request.

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