showtime on spectrum

FFT (Fast Fourier transformation) is a classic algorithm used for digital signal processing. Many people who have studied DSP or chip design know this algorithm. However, have you ever wondered why there are so many FFT operations in digital signal processing? Some may say that in order to analyze the signal spectrum. The problem below is to analyze the daily needs of the spectrum, such as mobile phone call

classes as membership functions cppclass4_demo2 (); // youyuan class cppclass4_demo3 (); return "view code and comments";} class CppClass4Demo1Time {public: cppClass4Demo1Time (int h, int m, int s) {_ hour = h; _ minute = m; _ second = s;} // youyuan function declaration: declare the global function string ShowTime (CppClass4Demo1Time ); is my friend function friend string ShowTime (CppClass4Demo1Time ); /

The features of the four wireless extended communication technologies are completely explained. First, let everyone understand the features of the wireless extended communication technology, and then fully introduce the features of the wireless extended communication technology. It does not matter. After reading this article, you will certainly have a lot of GAINS, I hope this article will teach you more things. The so-called spread-spectrum communica

The principle of PN Code synchronization in 1.CDMA system The transmitter and receiver adopt high accuracy and high stability clock frequency source to ensure the stability of frequency and phase. But in the practical application, there are many uncertain factors, such as the instability of sending and receiving clocks, uncertainty of launch time, transmission delay and interference, especially in mobile communication, these uncertainties are random, can not be compensated in advance and can on

of complex numbers.We know that in the real Fourier transform, its spectrum is 0 ~π (0 ~ n/2), but cannot represent the spectrum of-π~ 0, it can be foreseen that if the positive cosine is expressed in the plural form, it can be included in the negative frequency.Second, the variables before and after the transformation are considered plural formsThe complex form Fourier transform the original signal x[n] a

Js object-oriented object creation methods. For more information about how to create an object, see create an object: 1. Object literal volume. The Code is as follows: Var clock = {Hour: 12,Minute: 10,Second: 10,ShowTime: function (){Alert (this. hour + ":" + this. minute + ":" + this. second );}}Clock. showTime (); // call 2. Create an Object instance The Code is as follows: Var clock = new Object

Start to create an object:1. Object literal volume.Copy codeThe Code is as follows:Var clock = {Hour: 12,Minute: 10,Second: 10,ShowTime: function (){Alert (this. hour + ":" + this. minute + ":" + this. second );}}Clock. showTime (); // call 2. Create an Object instanceCopy codeThe Code is as follows:Var clock = new Object ();Clock. hour = 12;Clock. minute = 10;Clock. showHour = function () {alert (clock. ho

each otherTo make better use of the system bandwidth, the sub-carrier can be spaced as close as possible.Figure 12: Close to FDM, in practice, considering the hardware implementation, demodulation of the first signal, it is difficult to completely remove the impact of the second signal (the implementation of the circuit after all, can not be as neat as scissors cutting paper), the two signals may have caused interference with each otherCan you come closer? OK. This is the origin of OFDM, ah, ne

broadband access network business development in different regions and different application scenarios, the maximum bandwidth of VDSL2 can reach 30 MHz. For bandwidth below 12 MHz, the Plan997 and Plan998 bandwidths of VDSL are adopted. Among them, Plan997 is suitable for the application mode of Bidirectional symmetric rate of medium and short distance, while Plan998 is suitable for the application mode of downlink high speed of medium and short distance. Plan997 and Plan998 have a variety of e

Cognitive Radio (CR) technology effectively relieves the conflict between the lack of spectrum resources and the increasing demand for wireless access through secondary exploitation of the authorized spectrum, people are getting more and more attention. To enable CR users to use spectrum holes and avoid harmful interference to authorized users, the Media Access C

difficult to completely remove the impact of the second signal (the implementation of the circuit after all, can not be as neat as scissors cutting paper), the two signals may have caused interference with each otherCan you come closer? OK. This is the origin of OFDM, ah, nearly equal to the Nyquist bandwidth (detailed later), so that the frequency band utilization reached the theoretical maximum value.Figure 13: Continue closer, the interval frequency is orthogonal to each other, so the

Cognitive radio (CR) technology has been paid more and more attention by the way of "two utilization" of the authorized spectrum, which effectively relieves the contradiction between the lack of spectrum resources and the increasing demand for wireless access. In order to realize CR users ' use of spectrum holes while avoiding harmful interference to authorized

the page, and then apply these basic knowledge to create a real-time interaction system, such as sliding controls and dragging interfaces. 14.1 use of setTimeout and setinterval Both methods can be used to execute JavaScript after a fixed period of time. However, they have different application scenarios. Method In fact, setTimeout and setinterval have the same syntax. Both of them have two parameters. One is to be executed.CodeString, and a time interval in milliseconds. After that time period

BitsCN.com Adjustment of a composite index The table test is as follows: | Field | Type | Null | Key | Default | Extra | + ------------- + --------------------- + ------ + ----- + --------- + ------------------ + | Pid | int (10) unsigned | NO | PRI | NULL | auto_increment | | Tid | mediumint (8) unsigned | NO | MUL | 0 | | Showtime | int (11) | YES | 0 | Data Volume: over 200 million Originally, a composite index was created on tid and

The following table is used to adjust a composite index: | Field | Type | Null | Key | Default | Extra | + ------------- + ----------------------- + ------ + ----- + --------- + ------------------ + | pid | int (10) unsigned | NO | PRI | NULL | auto_increment | tid | mediumint (8) unsigned | NO | MUL | 0 | showtime | int (11) | YES | 0 | www.2cto.com has a data volume of more than 200 million. A composite index was originally created on tid and

have their own application scenarios. Method In fact, settimeout and setinterval have the same syntax. They all have two parameters, one is the code string that will be executed, and one is the time interval in milliseconds, and the code will be executed after that time period.However, these two functions are different, setinterval after the execution of the code, after the fixed time interval, it will also automatically repeat the code, and settimeout only one time to execute the code.Althou

Understanding of discrete Fourier transform (d)------complex form of discrete Fourier transform the discrete Fourier transform is very ingenious to use the complex method, making Fourier transform transformation more natural and concise, it is not simply to use the replacement method to use the complex Number, but to analyze the problem completely from the plural point of view, which is completely different from the real DFT.One, to represent a positive cosine function as a plural formThe positi

Understanding of discrete Fourier transform (d)------complex form of discrete Fourier transform the discrete Fourier transform is very ingenious to use the complex method, making Fourier transform transformation more natural and concise, it is not simply to use the replacement method to use the complex Number, but to analyze the problem completely from the plural point of view, which is completely different from the real DFT.One, to represent a positive cosine function as a plural formThe positi

1 Introduction More and more applications require sampling analog signals, converting them into digital signals, performing various calculations and processing on digital signals, and then converting them into analog signals. This article discusses how to sample analog signals and shaping them to preserve the original signal. 2 baseband signal sampling and mixing analysis Starting with the finite bandwidth signal, the finite bandwidth signal refers to the signal with a

Both methods can be used to execute JavaScript after a fixed period of time. However, they have different application scenarios. Method In fact, setTimeout and setinterval have the same syntax. Both of them have two parameters. One is to be executed.CodeString, and a time interval in milliseconds. After that time period, the code will be executed. However, there are differences between the two functions. After the setinterval code is executed, it automatically repeats the code after the fixed