Nowdays, a modern console can display many colors other than black and white. For example, 256-color can be enabled by adding the following entry into ~/.bashrc.
Linux - Microcode
Introduction
Microcode is a technique that imposes an interpreter between the hardware and the architectural level of a computer. Processor vendors, e.g., Intel and AMD, release updates to the processor microcode for some reasons, e.g., bug fixes, which can be applied by the Linux kernel during boot.
For AMD processors, the microcode is covered by package linux-firmware which is installed as part of the base system. Therefore, no specific processing is needed. While for Intel processors, it is not the truth. Package intel-ucode must be manually installed.
LTE - D2D
Overview
In LTE-Advanced systems, the link for D2D communication is termed sidelink 1. A sidelink carries two physical signals
- DMRS
- Synchronization signal
and four physical channels
- Physical sidelink shared channel (PSSCH)
- Physical sidelink control channel (PSCCH)
- Physical sidelink discovery channel (PSDCH)
- Physical sidelink broadcast channel (PSBCH)
PSSCH, PSCCH and PSDCH are all on the same antenna port, R1000. PSBCH and synchronization signals are on R1010 and R1020, respectively.
LTE - Discovery Signal
Just as its name indicates, discovery signal is transmitted by a cell to be discovered and measured by UE's. According to the standard1, a discovery signal occasion for a cell consists of
[Read More]LTE - Frequency Domain Location of Carriers
An LTE carrier, in principle, can be positioned anywhere within the spectrum range. In order to save the time consumption of carrier search for UE's, it is necessary to introduce additional restrictions on top of the specification.
[Read More]LTE - Mobility Management
The most remarkable character of mobile communication, which differs from other communication methods, is its mobility. The mobility can fall into two categories, intra-radio access technology (RAT) and inter-RAT mobility. Just as its name indicates, intra-RAT mobility means that the UE moves within one RAT, while inter-RAT mobility is the case that the UE move from one RAT to another. Namely, the source cell and the destination cell belong to two different RATs. Moreover, according to whether the destination cell operates on the same frequency as the serving cell, intra-RAT mobility can be further divided into intra-frequency and inter-frequency mobility two types.
[Read More]LTE - PDCCH & EPDCCH
Introduction
This post provides a brief summary on physical downlink control channel (PDCCH) and enhanced physical downlink control channel (EPDCCH) in long term evolution (LTE). Note the summary is based on the famous book, 4G, LTE-Advanced Pro and the Road to 5G1.
Machine Learning
Introducation
Machine learning (ML) is a subfield of artificial intelligence (AI).
Matched Filter
设时间\([0, T]\)内的观察信号\(r(t)\)为信号\(s(t)\)和噪声\(n(t)\)的叠加，也即 \[\begin{aligned} r(t) = s(t) + n(t), \quad t \in [0, T] \end{aligned}\] 如果要设计一个冲激响应为\(h(t)\)的滤波器，使得其输出在\(t = T\)时的信噪比(signal to noise power ratio, SNR)最大，这样的滤波器称为匹配滤波器(matched filter, MF)。其冲激响应为 \[\begin{aligned} h(t) = C s^*(T - t), \end{aligned}\] 其中，\(C\)为非零常数。
[Read More]MATLAB - Figure Data Abstraction
Provided a MATLAB figure file, e.g. FILE.fig, the original data can be abstracted by following procedure.