Lauro joined Award Solutions in 2008, bringing over ten years of experience in the wireless telecommunication industry working with mobile cellular, broadband and satellite communications. Has a thorough knowledge and understanding of all standardized radio transmission technologies (i.e.: GSM, GPRS, EDGE, WCDMA, HSxPA, HSPA+,IS-95, cdma 1xRTT, 1xEV-DO) and non-standardized technologies (i.e.: Flash OFDM, I-Burst, etc.) as well as and their migration path to 4G and beyond (LTE and WiMAX).
Lauro has co-authored four different telecommunication books, has published 18 international refereed journal papers and over 30 international conference papers, all of them results of research in the wireless telecommunication area. Additionally, has presented over 20 different wireless related courses nationally and internationally to a diverse class of clients. Lauro has a thorough knowledge of mathematical analysis and hands-on experience on wireless and traffic engineering design, including Design, Planning, Performance & Optimization as well as computer simulation of mobile wireless networks. Through research and computer simulation techniques has helped a large base of clients (carriers, vendors, new start up companies) develop optimum technological solutions.
Currently, Lauro is one of the instructors at Award Solutions. His current focus is UMTS, HSPA/HSPA+ and LTE. He is also involved in the development of cutting edge training on optimization courses for LTE operators in the USA.
Lauro holds a Ph.D. in electrical engineering (EE) from King's College London, UK (the University of London), a MSc. In EE. and a B.EE from the National Polytechnic Institute, Mexico, all of them with specialty in telecommunications.
In this blog a brief description of the motivations for LTE TDD (Time Division Duplexing) will be presented.
LTE supports three duplexing techniques:
a) FDD: In FDD mode, a pair of spectrum chunks is provided for in the uplink and downlink. At a given instant, transmission occurs in one spectrum chunk, and reception occurs in another spectrum chunk.
b) TDD: In this mode, the available frame duration is divided into different parts in the time domain for the uplink and downlink. The number of uplink and downlink subframes are (statically, in practice) configurable in TDD mode.
Half-FDD: H-FDD is a special case of FDD where an H-FDD device uses different frequencies to transmit and receive while communicating with an FDD eNB. However, it transmits and receives at different times.
For all the three modes of duplexing, OFDMA-based multiple access technology is used for downlink transmission. The SC-FDMA multiple access technology is used for uplink transmission in all the FDD, TDD and H-FDD modes.
So… Why TDD?
If FDD works, then why do we need LTE TDD? Well, there are clearly several advantages of TDD over FDD. Additionally, there are several reasons and motivations to deploy such system.