AnsweredAssumed Answered

AD9361 for wifi application

Question asked by henry1211 on Feb 7, 2017
Latest reply on May 5, 2017 by Vinod
Branched to a new discussion

hi all,

1. we have such wifi application, we are using 2T2R, and baseband will send 2 streams I0/Q0 and I1/Q1 with 40MHz clock to AD9361, since the max rate of 2T2R of TDD is 61.44MHz based on the UG-570, which can met our requirements, but the TDD mode for TX/RX switching time is about 20us, based on the below first link discussion(since the TX DAC power up is about 18us), which can not met the WLAN requirement for SIFS requirement, the SIFS time period is about 10us, considering the time cost of baseband, the WLAN TX/RX switching time should be less than 7us, so we are using the below second link suggestion, FDD independent Mode, and keep TX DAC always on, only enable/disable TX LO by config  0x051[D4], and TX/RX switching time can be "~160ns + SPI write", however 2T2R max rate of the FDD mode is only 30.72Mbps, which can not met our requirements, finally we decide to use LVDS mode, which can reach up tp 122.88Mbps. can anybody help us to confirm the above solution is ok or not? Or do you have some better solution for our case?

 

2. since we are in the phase of solution evaluation, based on searching our blog(the third link below), and find some saying that Ad9361 fast attack Mode of AGC can not lock in 4us, we want to know the solution for that issue, since we possibly will meet the same issue.

 

Running LTE-TDD by using FDD Independent Control Mode 

AD9361 for WiFi (TDD) application 

 

https://ez.analog.com/message/288128?commentID=288128&et=watches.email.thread#comment-288128 

Outcomes