Performance analysis of modified tent map interleaver in IDMA systems

Abstract

In the last years, Interleave Division Multiple Access (IDMA) has been presented as a potential alternate of Code Division Multiple Access (CDMA) system. In IDMA systems, the interleavers are used to separate the users of the system in multiple access environments. Random interleaver is popular and basic taxonomy, which scrambles information bits of craving users with different patterns. However the indispensable characteristics of a random interleaver such as bandwidth requirement, computational complexity, and memory restraint at both transmitter and receiver end is uttermost. Further, it has also been observed that the study of role of chaos in interleaver design is very limited in literature. Hence, in this paper, a low complexity chaos based interleaver named as modified Tent map interleaver is designed for further performance improvement of IDMA system and the characteristic parameters are compared with the random interleaver. The IDMA system model uses a BPSK modulation and repetition coder with a code rate of 1/2 . The system is simulated in MATLAB and results show that the better BER performance without the need of extra memory resources.K e y w o r d s: IDMA, tent map, chaos, random interleaver, computational complexity

Cooperative relay beamforming in IDMA communication networks

“…Each node consist a single antenna at sources and destination and communicating to each other without direct link due to path loss and deep shadowing between source and destination node. The relays used in network are AF relays and act as intermediate stage between source and destination so firstly the source sent their data to relays after spreading and interleaving operation and then in second stage the AF relays amplify and forward the data to the desired destination node [4,5] and [13][14][15][16] In a synchronous transmission, the received signal at the l th relay can be expressed as…”

“…Several relay protocols have been proposed on the basis of their relaying functionality such as Decode and forward (DF), amplify and forward (AF), compress and forward and cooperative cooperation. However large number of signal sources or relay nodes can lead to increase in multiple access interference (MAI), which can degrade the network performance [3][4][5][6][7][8]. Also the channel access schemes in relay networks are generally orthogonal which produce excess rate loss in the case of large number of users or relaying nodes as well as orthogonal schemes are having insufficient usage of time and frequency resources.…”

Performance Improvement of Idma Scheme Using Chaotic Map Interleavers for Future Radio Communication

“…Here, first the modified logistic map [15] is used for the generation of interleaver sequence. The NLM is described as,…”

“…Further the above system Eq. (5) However all of the above mentioned steps are repeated to get the second interleaver and so on [13][14][15]. …”

Design of equi-interference lines in CDMA mobile systems

“…Although coding algorithm in CDMA systems is designed in such a way that one interfering user has small effect on the reception of regular signal, the total influence of all interferers becomes significant [14]. The problem of MAI influence may be overcome in future by the implementation of Interleave Division Multiple Access (IDMA) systems [15].…”