Investigation on the probable effects on CDMA overlay existing analog FDMA systems | |
| Author | Nusorn Rukkasikorn. |
| Call Number | AIT RSPR no. TC-96-8 |
| Subject(s) | Code division multiple access Cellular radio |
| Note | A research study submitted in partial fulfillment of the requirements for the degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Series Statement | Research studies project report ; no. TC-96-8 |
| Abstract | This research study examines the probable effects of CDMA overlay on the existing analog FDMA system. CDMA cellular system considered is DS-CDMA system (IS-95 system) and FDMA cellular system is AMPS system. To analyze the effects of this overlay, assumptions are made such as: propagation path loss follows the fourth power law, every FDMA cell is overlaid by CDMA cell and for CDMA system, there is perfect power control scheme. We study the effects in the air interface thus we do not consider the effects occurring in transmitter and receiver. The effects concerning our interest are carrier-to-interference ratio (Cl!), capacity, frequency reuse efficiency and BER. The forward and reverse link of these effects of CDMA system under the influence of the FDMA system and the influence of CDMA system on the FDMA system are both examined. We investigate these effects by varying the number of users (both CDMA and FDMA users) and CDMA/FDMA power ratio. We discover that although overlay scheme can improve the overall capacity at average CDMA/FDMA power ratio, but the capacity of each system is decreased from without overlay condition for obtaining required (Cl!), frequency reuse efficiency and BER. However, the interference from FDMA system makes very poor performance of CDMA system. We find that CDMA system should use suppression technique for improving the CDMA performance. Applying this technique, we expect to have better CDMA performance and less influence on the existing FDMA system. We also find that forward link has less capacity than reverse link. |
| Year | 1996 |
| Corresponding Series Added Entry | Asian Institute of Technology. Research studies project report ; no. TC-96-8 |
| Type | Research Study Project Report (RSPR) |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Ahmed, Kazi Mohiuddin |
| Examination Committee(s) | Maketainen, Kimmo;Erke, Tapio J. |
| Degree | Research Studies Project Report (M.B.A.) - Asian Institute of Technology, 1996 |