dqpsk modulation

independent, the coverage area is not limited by the geographical condition, the bandwidth is wide, the capacity is big, is suitable for the multiple service transmission, may provide the global user with the big span, the wide range, the long-distance roaming and the mobile communication service and so on. In the DBS system, a large number of data by frequency division or time modulation after the use of satellite main station of the high-speed upli

signal over a larger frequency range. 3.3) 10gbase-t 10GBASE-T corresponds to the IEEE 802.3an standard published in 2006, and the goal of 10GBASE-T is to:-10-bit error rate (BER);-Data transmission speed of 100 meters long F-Class cabling (Class 7) up to million megabits per second;-Data transfer speed of 55 to 100 meters long E-Class cabling (class 6) reaches million megabits per second. The new CAT6A can reach a transmission distance of 100 meters, and the main differences between the 6a cla

, for sudden strong business flow, then choose TDMA mode; (3) The modulation mode of LMDS system is divided into two kinds of orthogonal phase shift keying (QPSK) and orthogonal amplitude modulation (QAM), in which QAM mainly adopts 4-qam, 16-qam,64-qam and so on, and the modulation mode on the downlink can choose Qpsk,16qam or 64QAM according to the specific co

and developing DPL technology, aimed at increasing its communication rate, at present, the world's leading companies in the United States Intellon Company has developed in the power line data transmission rate of up to 14mb/s communication system. There is no difficulty in transmitting audio, video on demand and real-time TV at such a rate, so DPL technology has aroused wide concern.The DPL technology uses improved Internet Protocol (IP) and complex dedicated electronic devices to transmit MHz

1. Ask modulation : "Amplitude shift keying" is also known as "amplitude keying", or "open key Control" (on-off keying), so it is also recorded as Ook signal. Ask is a relatively simple method of modulation. The amplitude shift keying (ASK) is equivalent to the amplitude modulation in the analog signal, except that the binary digital is multiplied by the carrier

Broadband Access Network is a mainstream access technology, and there are also many access methods. Here we mainly introduce the overview of VDSL and its working principles, including the characteristics of VDSL. Digital user line DSL is a constantly evolving broadband access network technology that uses advanced digital encoding and modulation and demodulation technologies to transmit broadband signals over conventional copper telephone lines. Curren

support more than 60 enterprise users or hundreds of home users who use E1/T1 at the same time. WiMAX uses a variety of advanced technologies, such as OFDM, diversity, and adaptive modulation, to achieve NLOS and block line of sight ONLOS transmission, effectively improving the efficiency of wireless transmission in the city. The physical layer supports TDD/DMTA and FDD/TDMA radio duplex multiplexing modes to meet the requirements of telecom systems

China's ADSL access technology has developed very rapidly. So I have studied the features and applications of the ADSL access technology. I would like to share with you here, hoping it will be useful to you. The maximum downlink rate of ADSL2 is 12 Mb/s due to improved frame structure and optimized RS encoding. Because ADSL2 + uses a wider spectrum, there are more than 512 sub-carriers). When the distance is short, the downlink speed can reach up to 24 Mb/s. If g.992.32.16j is used, the maximum

range of roaming and flexible mobile communication services. In the DBS system, a large amount of data is broadcasted using the High-Speed Uplink Channel of the satellite Main Station and the satellite forwarder after the frequency division or time division modulation, the user receives data through the satellite antenna and satellite Modem, and the receiving antenna is generally 0.53 m or m in diameter. Because the digital satellite system has high

The development of networks is immeasurable. With the broadband access of ADSL, every household can access the Internet at high speed. Therefore, ADSL is constantly improved to achieve higher speed and wider bandwidth. Now let's take a look at the differences between ADSL2 and ADSL2 +. Due to frame structure improvement and optimized RS encoding, ADSL2 can reach a maximum downlink rate of 12 Mb/s. because ADSL2 + uses a wider spectrum, there are more than 512 sub-carriers). When the distance is

system to the 100 Gbit/s OTN system, the following requirements must be met: 1) supports 50 GHz channel spacing; 2) dispersion (CD) margin ± 700 ps/nm; 3) polarization modulus dispersion (PMD) margin of 10 ps (DGD average value ); 4) It can be smoothly upgraded in the existing DWDM network and OTN network; 5) there is no major crosstalk cost for existing DWDM channel signals. 100 Gbit/s OTN system upgrade requirements must meet all of the above requirements, currently can through coherent detec