User-specific chip-level interleaver design for IDMA systems

The demand for wireless broadband communication services has been growing steadily for last several years. Over the last two decades, wireless communications have gained enormous popularity in all over the world. It offers an attractive option requirement due to various parameters including cost, effectiveness, and mobility. The next generation mobile communication systems i.e. fourth generation (4G) are needed to support multiple services in different types of environments. 4G is being developed to accommodate the QoS (quality of service) and required data rate such as wireless broadband access, Multimedia Messaging Service (MMS), video chat, mobile TV. This paper focuses the light on various multiple access techniques proposed in 4G communication systems. Among all the multiple access (MA) techniques, it is attempted to demonstrate that IDMA (Interleave Division Multiple Access) technology can efficiently mitigate the interference among users and support high data rates without compromising the required quality of service Keywords-CDMA, IDMA, Multiple access Interleavers, Multi user detection.

Wireless Communications and Mobile Computing, 2009

In this paper, we propose a new tree based interleaver (TBI) to generate different chip-level interleaving sequences for different users in an interleave division multiple access (IDMA) system, which reduces computational complexity. This method of generation also solves the memory cost problem and reduces the amount of information exchange between mobile stations (MSs) and base stations (BSs) required to specify the interleaver. Simulation results are presented to show that the proposed interleavers perform well as compared to random interleavers in an IDMA system.

Proceedings of the 2008 16th International Conference on Networks, ICON 2008, 2008

Here, we propose a novel Tree Based Interleaver (TBI) for generating user specific chip-level interleaving sequences for various users in an IDMA system, which reduces computational complexity drastically. This interleaver also solves the memory cost problem and reduces the amount of information exchange between mobile stations and base stations required to specify the interleaver. Simulation results are presented to show that the proposed TBI perform well as compared to Master Random and Random Interleavers in an IDMA scheme.

IEEE Transactions on Vehicular Technology, 2000

This paper presents a novel generalized transceiver architecture, i.e., Multicarrier Interleave-Division-Multiplexingaided Interleave Division Multiple Access (MC-IDM-IDMA). A parallel interference cancellation (PIC)-aided iterative multiuser detection (MUD) algorithm is introduced, and the convergence behavior of the system is evaluated with the aid of EXtrinsic Information Transfer (EXIT) charts under the assumption of an equal-power multiuser scenario. Three interesting design tradeoffs of the MC-IDM-IDMA system are analyzed: 1) the multiplexing versus diversity tradeoffs; 2) the coding versus spreading tradeoffs, where the achievable bandwidth efficiency of both MC-IDM and MC-IDMA are characterized, and a general design rule is provided for low-rate codes; and 3) the complexity versus performance tradeoffs and the EXIT characteristics of two different MUD algorithms are investigated, leading to a reducedcomplexity hybrid MUD. Index Terms-EXtrinsic Information Transfer (EXIT) charts, interleave division multiplexing/interleave division multiple access (IDM/IDMA), multicarrier (MC), multiuser detection (MUD). I. INTRODUCTION B ASED ON the chip-interleaved code-division multipleaccess (CDMA) philosophy of Frenger et al. [1] and Mahadevappa and Proakis [2], the interleave-division multipleaccess (IDMA) philosophy was further developed by Ping et al. [3], [4] and Schoeneich and Hoeher [5], [6]. IDMA entails reversing the classic position of direct sequence (DS) spreading (S k) and interleaving (π) employed in traditional CDMA systems [7], leading to chip interleaving instead of bit interleaving, where the different users are distinguished by their unique userspecific chip interleavers π k. The benefits of single-carrier (SC) IDMA are the following: 1) random coding, 1 where different users have unique random signatures; 2) time diversity, where chip interleaving is capable of increasing the achievable time diversity in time-selective channels; and 3) joint coding and spreading design, which is capable of improving the attainable bandwidth efficiency and error resilience.

Few basic requirements for future wireless 4G systems includes low receiver cost, decentralized (i.e. asynchronous) control, simple treatment of ISI, cross cell interference mitigation, diversity against fading, power efficiency (long battery life), multimedia services, high user number, high throughput and high spectral efficiency. All theses factors mentioned are not fulfilled by any multiple access techniques at present. Interleave-Division Multiple-Access (IDMA) is a technique, which provides better result during simulation when applied with at least few of the future mobile communication requirements. IDMA employs interleavers as the only means in order to distinguish the users. This paper provides a comprehensive study of IDMA technique with orthogonal interleavers. . Index Terms--IDMA, Tree Based Interleaver, Multiple Access Interference.

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 2009

Power allocation with unequal strategy, is a technique to further enhance system performance in multiple access schemes. This paper is basically related with the performance enhancement of iterative IDMA systems using unequal optimum power allocation algorithm. Here, we compare the performance of coded and uncoded IDMA system with random interleaver & tree based interleaver. The simulation results demonstrate the superior performance of tree based interleaver in comparison to random interleaver in view of memory requirement along with similar BER performance.

2007

Interleave Division Multiple Access (IDMA) is a multiuser scheme which enables user separation on the basis of interleavers. Interleaver design can allow the IDMA system to approach near Shannon limits of channel capacity. Interleaver combats against Intersymbol Interference (ISI), channel fading and all sorts of noises. In addition, interleavers provide security to the system users. Designing the random interleaver provides a solution for all impairments but they are generally considered computationally heavy. In this paper, an efficient approach has been developed for design of user specific random block interleavers. This design approach reduces the complexity for developing interleaving patterns and is computationally economical.

SSRN Electronic Journal, 2000

This paper outlines a multiple access technique which exploits the interleaving as only means of user separation instead of by different signatures as in a conventional codedivision multiple-access (CDMA) scheme. It examines a very simple iterative chip-by-chip multiuser detection strategy for spread spectrum communication systems. The given scheme can achieve near single user performance in situations with very large numbers of users while maintaining very low receiver complexity. This technique shows that high performance can be maintained in multipath environments. IDMA inherits many advantages from CDMA, such as diversity against fading and mitigation of the worst-case user interference problem. A low-cost iterative chip-by-chip multiuser detection algorithm is also described with complexity independent of the user number and increasing linearly with the path number.

This paper present a review on the concept of Interleave Division Multiple Access (IDMA) which exploits the interleaving as only means of user separation. In this paper, different interleavers have been compared based on bit error rate. Finally it concludes few ideas on the future scope and challenging issues in this scheme.

2018

This paper provides a review on the IDMA (Interleave Division Multiple Access) technology in wireless communication system based on Interleaver. In this paper, IDMA technique is proposed in AWGN channel. IDMA is a multiuser scheme in which chip Interleavers are the only means of user separation. The IDMA performance in terms of bit error rate, error rate is discussed. Here comparision with different sources is done on the basis of error rate and various different parameters.