We have two goals in this paper. One is the comparison of Spread Spectrum (SS) CDMA and Spread Time (ST) CDMA. The other is to propose a new SS-ST CDMA system, which is an adaptive CDMA with both merits of SS and ST CDMA. SS and ST CDMA are compared from the view point of two dimensional space "frequency (B Hz) time (T Sec) " together with their communication capacity. A primary modulation is a...

3 Scheduling-based mechanism 8 3.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.2 CDMA ad hoc networks . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2.1 CDMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2.2 CDMA ad hoc networks . . . . . . . . . . . . . . . . . . . . . 11 3.3 TDMA . . . . . . . . . . . . . . . . . . . . . . . . . . ...

This paper proposes a broadband wireless transceiver which can be reconfigured to any type of cyclic-prefix (CP) -based communication systems, including orthogonal frequency-division multiplexing (OFDM), single-carrier cyclic-prefix (SCCP) system, multicarrier (MC) code-division multiple access (MC-CDMA), MC direct-sequence CDMA (MC-DS-CDMA), CP-based CDMA (CP-CDMA), and CP-based direct-sequenc...

This letter presents a novel multi-carrier code division multiple access (MC-CDMA) system called time domain synchronous MC-CDMA (TDS-MC-CDMA). Aided by the new training sequence (TS) with perfect autocorrelation in the time domain and flat frequency response in the frequency domain, the proposed TDS-MC-CDMA system outperform the traditional MC-CDMA system in terms of spectrum efficiency by abo...

| Multicarrier CDMA and direct sequence CDMA have been suggested for both narrowband and broadband multiple access systems. A series of concepts have further been proposed for variable rate broadband transmission within a CDMA system. These principally diierent techniques exhibit certain common characteristics that can be exploited. In this paper we propose a generalised unifying discrete-time ...

برای دستیابی به مزیت رقابتی در شرایط عدم‌­اطمینان که آن تغییر ضروری است، یکی از چالش‌های بزرگ سازمان‌ها کاهش ریسک طریق ایجاد زنجیره‌های تأمین تاب‌آور است. تاب‌آوری زنجیره ‌تأمین توانایی مقابله با اختلال اشاره دارد یک رویداد غیرقابل‌پیش‌بینی بوده و دارای منابع داخلی خارجی مختلفی ازجمله بلایای طبیعی ریسک‌های عملیاتی پژوهش حاضر شبیه‌سازی توسط نرم‌افزار ارنا زنجیره‌ سنگ ساختمانی «کارخانه سنگبری آسم...

Multi Carrier Code Division Multiple Access (MC-CDMA) is a well known technique for high speed wireless data transmission .Two advanced technology was included in the MC-CDMA structure, such as orthogonal frequency division multiplex (OFDM) and the code division multiple access (CDMA),so that it benefits from the robustness of OFDM against multipath environment and from the capability of multiu...

CSIM19 is the latest version of the system modeling toolkit from Mesquite Software. CSIM19 offers many features that enable a modeler to develop robust and realistic models of complex systems. These models represent the system as a collection of processes and resources; in most cases the processes mimic the behavior of the entities of the system as they compete for use of the system’s resources...

Code-division multiple-access (CDMA) multiuser detection is a kind of signal recovery problem. The main problem CDMA to estimate the original from degraded information. In detection, first-order phase transition happens. degrades estimation performance. To avoid or mitigate transition, we apply adiabatic reverse annealing (ARA) detection. ARA, introduce initial Hamiltonian, which corresponds pr...

Over the past several years there has been increased interest in wireless mobile communication systems that use code division multiple access (CDMA). The systems such us IS-95 (Direct Sequence CDMA, DS-CDMA) and UMTS (Wideband CDMA, W-CDMA) already use CDMA based techniques. On the other hand, thanks to excellent multi carrier (MC) modulation properties in the frequency selective fading radio c...