Felipe Augusto Pereira de Figueiredo

9 Questions 15 Answers 0 Followers

Questions related from Felipe Augusto Pereira de Figueiredo

Which frequency band is the most suitable for RIS deployment?

Which frequency band is the most suitable for RIS deployment? Have RIS-aided systems the same advantages for low frequency bands such as 800 MHz/2 GHz and high frequencies such as mmWave/THz bands?

18 December 2020 4,819 4 View

Can the correlation matrices of correlated Rayleigh channels between a Massive MIMO BS and a LIS be considred equal?

Let's say a BS equipped with a massive mimo array communicates with a LIS array through a correlated Rayleigh channel. Can we say that the correlation matrices of the channels between the BS and...

17 May 2020 442 0 View

What is the PDF of the finite sum of the product of independent but non-identically distributed Rayleigh random variables?

What would be the PDF of the finite sum (i.e., the sum of N product terms) of the product of two independent but non-identically distributed Rayleigh random variables? Does someone know what the...

27 January 2020 395 9 View

Which channel correlation model is the hardest and which one is the closest to real-world case?

In the paper “Massive MIMO Has Unlimited Capacity”, the authors used three different channel correlation models and I was wondering which one is the closest one to the real-world case and which...

17 November 2019 699 3 View

Is there a better channel estimator than MMSE for i.i.d. Rayleigh channels?

Given i.i.d. Rayleigh fading, known (at BS) large scale-fading parameters and pilot based channel estimation for a Massive MIMO system, can we have a better channel estimator than the one achieved...

26 February 2018 4,040 6 View

What is the length of pilots in a practical massive MIMO system?

I've seen some practical deployments that are based on LTE(-A) technology, which uses TTIs of 1 ms. In those systems, assuming that the coherence time is greater than 1 ms, where for normal CP we...

25 February 2018 151 1 View

Is the covariance matrix of linearly independent channels symmetric?

In [1] the authors consider linearly independent channel covariance matrices, however, they do not mention if it is symmetric or not. Therefore, I'd like to know if the covariance matrix for that...

25 January 2018 2,096 4 View

How would I model a frequency-selective channel (e.g., a 2 tap channel) in terms of small and large scale fading for a massive MIMO study?

On its seminal paper, Dr. Thomas Marzetta, considers the the complex propagation cofficients into the frequency domain, however, for my study I need to know how the coefficients would be into time...

11 February 2016 7,031 3 View

Why does the SCell need to be time-synchronized to the PCell in LTE-LAA deployments?

My question regards the real necessity to have subframe (3GPP Rel. 12) or slot (3GPP Rel. 13) aligned transmissions in the unlicensed band. According to TR 36.889: "Channel reservation refers to...

01 January 1970 7,842 4 View