| Author | Myo Tun |
| Call Number | AIT Thesis no.TC-00-08 |
| Subject(s) | Code division multiple access
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of
Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. TC-00-08 |
| Abstract | Parallel and Serial Concatenated Trellis Coded Modulation schemes (T-TCM and SCTCM)
are investigated to improve the spectral efficiency with acceptable bit error rate
performance of the multicarrier CDMA (MC-CDMA) system for the downlink mobile
communication channel. For T-TCM, recursive systematic Trellis Coded Modulation (TCM)
codes are used as the component codes of the encoder and the overall coding rate is 2/3 with
8-PSK modulation. For SC-TCM, an outer rate 1/2 recursive systematic convolutional
encoder and an inner rate 2/3 TCM encoder are connected by an interleaver. Overall coding
rate is 1/3 with 8-PSK modulation. For both cases, a pairwise pseudorandom interleaver of
length 1024 is used.
The system is considered for 32 users. Bit error rate (BER) performance of the MCCDMA
with both types of coding is evaluated with different types of combining techniques
(MRC and MMSEC) and different mobile speeds (5 km/hr and 100 km/hr) as a function of
signal to noise ratio (Eb/N0 ). BER of the uncoded case is also evaluated. BER performance of
the power control MC-CDMA system with maximum ratio combining (MRC) for full
loading is also evaluated.
Based on the simulation results, for the same transmitted signal bandwidth, it has
been found out that the performance of SC-TCM is well suited for low source data rates (512
kb/s) and low power transmission with reduced decoding complexity and T-TCM is for high
source data rates (1024 kb/s) with the requirement ofrelatively high power transmission. But
for the same source data rate, the bandwidth requirement of SC-TCM is exactly two times
than that ofT-TCM. Therefore, T-TCM is also suited for the limited spectrum area where the
available bandwidth is limited to a certain amount. From the spectral efficiency point of
view, we can save spectral efficiency three times for SC-TCM and six times for T-TCM if
we compared with rate 1/3 Turbo coded case using BPSK modulation. Finally, it can be
found that both of these types of coding schemes with MC-CDMA system can be useful in
third generation mobile communication systems because high spectrum efficiency is one of
the main objectives of the International Mobile Telecommunication (IMT-2000) standard. |
| Year | 2000 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. TC-00-08 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Rajatheva, R.M.A.P. ; |
| Examination Committee(s) | Ahmed, Kazi M.;Teerapat Sa-nguankotchakom; |
| Scholarship Donor(s) | Government of Finland; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2000 |