dwdm spectrum

With the development of the communication network towards broadband and mobile, the optical fiber wireless communication system (ROF) integrates Optical Fiber Communication and wireless communication, giving full play to the advantages of broadband and anti-interference of optical fiber lines, at the same time, it makes full use of the convenient and flexible wireless communication to meet people's needs for broadband. Early ROF technology was designed to provide high-frequency wireless transmis

With the rapid development of wireless communication technology, spectrum resources, especially those under 3 GHz, become increasingly tense. Due to the emergence of Wireless LAN technology and wireless network technology, more and more people are using these technologies to connect to the Internet and telecommunication networks wirelessly. Most of these technologies use non-authorized frequency bands to make these frequencies saturated. However, some

Summary Starting from the analysis of GSM spectrum efficiency, this paper analyzes the loss of spectrum efficiency of voice service after the GSM network is upgraded to GPRS, and the new data service access ability, and finally takes into account the maximum access ability of the integrated service under GSM current spectrum from the mutual substitution between

light Single-Mode Optical Fiber: optical fiber that transmits light forward without multiple reflections Frequency Division Multiplexing (OFDM): After a user allocates a certain frequency band, the user occupies this frequency band throughout the communication process. All users use different bandwidth resources at the same time. Time division multiplexing (TDM): divides the time into long time division multiplexing frames (TDM frames) such as segment. Each time division multiplexing user occup

transmission rod routes are generally optical fiber cables and power cables mixed into one pole for transmission.1.3 SDH TransmissionSDH is called the Synchronous Digital System, which unifies the rate level, network node interface NNI, and frame structure of digital communication. SDH is to synchronous transmission module STM form to transmit, according to the level divided into STM-1: 155 Mbit/s (155), can accommodate 63 2 m; STM-2: 622 Mbit/s (622), can accommodate 4 155; STM-3: 2.5 Gbit/s (

In recent years, the main development trends of optical communication technology include capacity improvement, further intelligence, optical transmission of Carrier-class Ethernet, and fiber-to-the-Home. Along with the development of these technologies, optical communication testing technology has also developed rapidly. The development of the optical communication industry depends on the drive of the market and the development of technology. In recent years, the main development trends of optic

During the course of study, this parameter is often used. Later I worked mainly on audio/speech codec, but the concept of cepstrum was rarely used. I saw these words when I read a paper today, I think it is very practical. Let's review this signal feature. Time-cepstrum analysis is very effective when extracting the signal characteristics transmitted by the carrier. Cepstrum is widely used in the extraction of Speech Recognition feature parameters. This is because the essence of speech is the

to implement spectrum analysis or other work on the computer. The computer's requirement for signals is that both the time domain and frequency domain must be discrete and must be finite. While Fourier transform (FT) can only process continuous signals, DFT is born in response to such a need. It is the representation of Fourier transformation in discrete fields. However, in general, the calculation of DFT is very large. Before the first high-speed Fo

, signal processing, and other fields. We hope to implement spectrum analysis or other work on the computer. The computer's requirement for signals is that both the time domain and frequency domain must be discrete and must be finite. While Fourier transform (FT) can only process continuous signals, DFT is born in response to such a need. It is the representation of Fourier transformation in discrete fields. However, in general, the calculation of DFT

to implement spectrum analysis or other work on the computer. The computer's requirement for signals is that both the time domain and frequency domain must be discrete and must be finite. While Fourier transform (FT) can only process continuous signals, DFT is born in response to such a need. It is the representation of Fourier transformation in discrete fields. However, in general, the calculation of DFT is very large. Before the first high-speed Fo

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

-called "frontend network" refers to the egress of the data center for enterprise campus network or enterprise wide area network. Frontend networks of different data centers (primary centers and disaster recovery centers) are interconnected through IP technology, and clients of the campus or branch access data centers through the frontend network. When a disaster occurs in the primary data center, the front-end network is quickly converged, and the client accesses the disaster recovery center to

early detection Advanced ASIC RTP, RTCP Double funnel universal cell rate algorithm Dwdm Rsvp Rated access crash rate Sonet Diffserv, CAR Cisco Express Forwarding CPU processing power g.729, G.729a:cs-acelp Extended Access table Adsl,radsl,sdsl frf.11/frf.12 Token bucket algorithm Multilink PPP Frame Relay D

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

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

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

power monitoring circuit monitors the changes in the optical power value of the active and standby optical fibers in real time. It has a built-in photoelectric sensor and a 1 × 2 optical splitter. The optical splitting ratio is usually 97: 3, this is equivalent to increasing the attenuation of about 0.25 dB on the transmission line, and is suitable for online applications. The optical switching circuit has a built-in 1X2 or 2x2 optical switch, which is controlled to automatically switch between

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