Broadband wireless data transimission through LMDS : a case study in Ho Chi Minh City | |
| Author | Hoang Nam Thang |
| Call Number | AIT RSPR no.TC-05-11 |
| Subject(s) | Broadband communication systems--Vietnam Wireless communication systems--Vietnam Data transmission systems--Vietnam |
| Note | A research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering, school of Advanced Technologies |
| Publisher | Asian Institute of Technology |
| Series Statement | Research studies project report ; no. TC-05-11 |
| Abstract | In this research study, we study Local Multipoint Distribution System (LMDS) in the aspect of providing the medium for broadband data transmission such as HDTV signal. As we know that LMDS is currently a promising teclmology in broadband fixed wireless communications. The system supplies transmissions of high data rates of up to 52 Mbit/s for downlink chaimel and 3 Mbit/s for uplink channel with path availability of more than 99.99%. Therefore, many services, such as multimedia service, digital television, and interactive service, can be supported by LMDS. However, the system uses cellular structure with line of sight path and operates at around 30 - 40GHz, so the attenuation caused by rain, path loss and losses due to vegetation are significant and needed to be considered carefully. Moreover, inter-symbol interference (ISI) caused by multipath propagation channel in LMDS is also a considerable problem. Using 01ihogonal Frequency Division Multiplexing (OFDM) technique is a solution to overcome this problem. Since each OFDM sub-carrier occupies a variable narrow spectrum, one tap equalizer is usually used for each sub-carrier to correct channel dist01iion. On the basic of this technology, this research study simulates HDTV transmission in order to compare the bit etTor rate (BER) performance of LMDS with and without OFDM, for transmitting HDTV through LMDS in three-channel model including A WGN, Rician and Time variant cha1mel. In addition, the attenuation due to rain, frequency and other factors are calculated for the transmit power, the link budget in this research. The result shows that with number of transmitted bits of 107 , performance remains with in I 0-3 without OFDM, whereas with OFDM, we can improve the BER to I 0-5 for our case. |
| Year | 2005 |
| Corresponding Series Added Entry | Asian Institute of Technology. Research studies project report ; no. TC-05-11 |
| Type | Research Study Project Report (RSPR) |
| School | School of Advanced Technologies (SAT) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Ahmed, Kazi Mohiuddin; |
| Examination Committee(s) | Erke, Tapio J.; Rajatheva, N.; |
| Scholarship Donor(s) | Ho Chi Minh City Post and Telecommunications, Viet Nam; |
| Degree | Research report (M.Sc.) - Asian Institute of Technology, 2005 |