Channel State Information Reference Signal (CSI-RS)

Sun, 02 Jul 2023 00:00:00 +0000

Introduction

In NR system, channel state information reference signal (CSI-RS) plays a variety of roles, including

CSI measurement
Beam management
Tracking
Mobility management
Rate match

Generally, there are two types of CSI-RS, termed non-zero-power (NZP) CSI-RS and zero-power (ZP) CSI-RS, respectively. The former is configured by .

Sequence Generation

CSI-RS symbols are a sequence of QPSK-modulated Gold sequence, which is initialized with

\begin{align*} c_{\text{init}} = \left[ 2^{10}(N_{\text{symb}}^{\text{slot}}n_{s,f}^{\mu} + \ell + 1)(2n_{\text{ID}}+1) + n_{\text{ID}} \right] \mod 2^{31} \end{align*}

where

$N_{\text{symb}}^{\text{slot}}$ is the number of symbols in a slot.
$n_{s,f}^{\mu}$ is the index of the slot within a frame.
$\ell$ is the index of the symbol within a slot.
$n_{\text{ID}}$ is configured by .

Rs on Shaka

Channel State Information Reference Signal (CSI-RS)

Introduction

Sequence Generation