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The advantage of using wireless data transmission module... Data transmission can be simply divided into two major types: wired (including the installation of optical cables, cables or leased telecommunication lines) and wireless (including the establishment of dedicated wireless data transmission system or the borrowing of CDPD, GSM, CDMA and other public network information platforms).     In...

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Industrial-grade 4G router TCP/IP network architecture 1. Layering of TCP/IP network system   TCP/IP (TransmissionControlProtocol/InternetProtocol), transmission control protocol/Internet protocol. It was developed by the defense advanced research projects agency in the 1970s, and was later integrated into UNIX and popularized. It emerged in the 1980s as the Internet's...

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The structure of 4G DTU The main function of DTU is to transmit data from remote devices back to the background center via wired/wireless. Different data transmission modes of DTU include all-network-connected DTU, GPRS DTU, WIFI DTU, CAN DTU and 4G DTU. Today, we will have a look at the structure and work flow of DTU.   To complete...

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What are the wireless connection technologies of the... Internet of things (iot) applications have been deeply rooted in our lives. The E-Lins H685 industrial-grade router is a small industrial-grade wireless router with single or double LAN ports. TDD/ fdd-lte, 4G, 3G, GPRS network optional. Besides, what are the wireless connectivity technologies for the Internet of things?   1....

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The use of industrial wireless routers Industrial-grade wireless router adopts high performance 32-bit industrial-grade ARM9 communication processor, which is widely used in finance, electric power, postal, water conservancy, environmental protection, meteorology and other industries.   Industrial router is mainly used in intelligent transportation,...

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TDD LTE and FDD LTE

文章目录 : 技术相关

As we know, the LTE mainly covers two types, which are TDD and FDD.  Let’s talk something about TDD LTE and FDD LTE’s Advantages / disadvantages of for cellular communications.

There are a number of the advantages and disadvantages of TDD and FDD that are of particular interest to mobile or cellular telecommunications operators. These are naturally reflected into LTE.

COMPARISON OF TDD LTE AND FDD LTE DUPLEX FORMATS
PARAMETER TDD LTE FDD LTE
Channel reciprocity Channel propagation is the same in both directions which enables transmit and receive to use on set of parameters Channel characteristics different in both directions as a result of the use of different frequencies
Paired spectrum Does not require paired spectrum as both transmit and receive occur on the same channel Requires paired spectrum with sufficient frequency separation to allow simultaneous transmission and reception
Hardware cost Lower cost as no diplexer is needed to isolate the transmitter and receiver. As cost of the UEs is of major importance because of the vast numbers that are produced, this is a key aspect. Diplexer is needed and cost is higher.
UL / DL asymmetry It is possible to dynamically change the UL and DL capacity ratio to match demand UL / DL capacity determined by frequency allocation set out by the regulatory authorities. It is therefore not possible to make dynamic changes to match capacity. Regulatory changes would normally be required and capacity is normally allocated so that it is the same in either direction.
Guard period / guard band Guard period required to ensure uplink and downlink transmissions do not clash. Large guard period will limit capacity. Larger guard period normally required if distances are increased to accommodate larger propagation times. Guard band required to provide sufficient isolation between uplink and downlink. Large guard band does not impact capacity.
Cross slot interference Base stations need to be synchronised with respect to the uplink and downlink transmission times. If neighbouring base stations use different uplink and downlink assignments and share the same channel, then interference may occur between cells. Not applicable
Discontinuous transmission Discontinuous transmission is required to allow both uplink and downlink transmissions. This can degrade the performance of the RF power amplifier in the transmitter. Continuous transmission is required.

 

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