Jiajun Zhu

9 Questions 12 Answers 0 Followers

Questions related from Jiajun Zhu

How to determine whether or not the Power amplifier has memory effect, via tests or experiments?

The non-linearity of power amplifier limits the power output efficiency. So, we can use DPD technique to improve it. But we need to know the power amplifier with the memory effect or memory-less....

13 September 2018 6,009 6 View

How do I design a loop filter of DPLL in OFDM system?

Hi all, I am designing a loop filter of DPLL in 802.11ac OFDM system. The DPLL tracking is achieved by pilot symbols inserted into OFDM symbols. Importantly, the coefficients of loop filter...

04 February 2016 9,159 3 View

Does anyone know how to compute the soft output (LLR) of MIMO ZF-SIC/MMSE-SIC detector?

As for linear ZF or MMSE detector, the coefficient of soft output is that symbol power over symbol interference power plus white noise power. As for non-linear ZF-SIC or MMSE-SIC detector, the...

16 October 2015 6,416 4 View

Does anyone know how to solve the mismatch sampling rates between 802.11ac multipath channel and baseband signal?

I am studying how to establish a 802.11ac multipath channel for my WiFi simulation. As we know, the impact of channel is equivalent to that the transmit signal go through a "channel filter"....

20 August 2015 2,024 6 View

Does anyone know how to calculate the LLR of MIMO ZF-SIC or MMSE-SIC?

Hi all, In linear MIMO ZF or MMSE, the LLR is calculated by detected signal power over both interference noise power and white noise power. In nonlinear MIMO ZF-SIC and MMSE-SIC, the interference...

04 August 2015 6,537 1 View

How can I simulate the algorithm for a IEEE802.11ac PHY layer that can optimally reflect the performance of a real-circuit implementation?

I am working for a semi-conductor company. Now, my assignment is to design IEEE802.11ac PHY layer algorithm. However, the situation of theoretical simulation is very different from that of...

11 May 2015 6,878 6 View

Does anyone know the advantages and disadvantages of LBER equalizer compared with MMSE equalizer?

Further, could anyone provide some references introducing this technique in detail? Many thanks

01 September 2014 4,181 1 View

Does anyone know how to determine the value of step size in LMS algorithm.?

I wanna to establish a inverse modelling to get a equalizer to combat the multipath channel. However, I found a problem that the training of LMS algorithm is very unstable under the Rayleigh...

22 August 2014 1,027 17 View

Does anyone know some references about Decision Feedback Equalizer (DFE) ?

I want to design a Decision Feedback Equalizer (DFE) to combat the multipath channel. Does anyone know some references about the principles of Decision Feedback Equalizer (DFE) ? Further, What is...

20 August 2014 5,349 4 View