SIMULATION OF A CODE DIVISION MULTIPLE ACCESS (CDMA) 2000 DOWNLINK SYSTEM

The topic chosen for this project is the simulation of a CDMA 2000 downlink system. CDMA 2000 is a 3G mobile telecommunications standard that uses CDMA to send voice, data and signaling data (such as a dialed telephone number) between mobile telephones and cell sites. The purpose of the simulation is to show that the design of the system can be implemented in actual application. The original codes and libraries aretaken directly from the Matlab software for the purpose of the simulation. The simulation is set up by considering the data rate, the channel model and also the performance of the system in terms of bit error rate results and the frame quality indicator. I

On the Interaction between TCP and the Wireless Channel in CDMA2000 Networks

In this work, we conducted extensive active measurements on a large nationwide CDMA2000 1xRTT network in order to characterize the impact of both the Radio Link Protocol and more importantly, the wireless scheduler, on TCP. Our measurements include standard TCP/UDP logs, as well as detailed RF layer statistics that allow observability into RF dynamics. With the help of a robust correlation measure, normalized mutual information, we were able to quantify the impact of these two RF factors on TCP performance metrics such as the round trip time, packet loss rate, instantaneous throughput etc. We show that the variable channel rate has the larger impact on TCP behavior when compared to the Radio Link Protocol. Furthermore, we expose and rank the factors that influence the assigned channel rate itself and in particular, demonstrate the sensitivity of the wireless scheduler to the data sending rate. Thus, TCP is adapting its rate to match the available network capacity, while the rate allocated by the wireless scheduler is influenced by the sender's behavior. Such a system is best described as a closed loop system with two feedback controllers, the TCP controller and the wireless scheduler, each one affecting the other's decisions. In this work, we take the first steps in characterizing such a system in a realistic environment

TCP over CDMA2000 Networks: A Cross-Layer Measurement Study

Modern cellular channels in 3G networks incorporate sophisticated power control and dynamic rate adaptation which can have significant impact on adaptive transport layer protocols, such as TCP. Though there exists studies that have evaluated the performance of TCP over such networks, they are based solely on observations at the transport layer and hence have no visibility into the impact of lower layer dynamics, which are a key characteristic of these networks. In this work, we present a detailed characterization of TCP behavior based on cross-layer measurement of transport layer, as well as RF and MAC layer parameters. In particular, through a series of active TCP/UDP experiments and measurement of the relevant variables at all three layers, we characterize both, the wireless scheduler and the radio link protocol in a commercial CDMA2000 network and assess their impact on TCP dynamics. Somewhat surprisingly, our findings indicate that the wireless scheduler is mostly insensitive to channel quality and sector load over short timescales and is mainly affected by the transport layer data rate. Furthermore, with the help of a robust correlation measure, Normalized Mutual Information, we were able to quantify the impact of the wireless scheduler and the radio link protocol on various TCP parameters such as the round trip time, throughput and packet loss rate

Downlink Steered Space-Time Spreading Assisted Generalised Multicarrier DS-CDMA Using Sphere-Packing-Aided Multilevel Coding

This paper presents a novel generalised Multi-Carrier Direct Sequence Code Division Multiple Access (MC DS-CDMA) system invoking smart antennas for improving the achievable performance in the downlink, as well as employing multi-dimensional Sphere Packing (SP) modulation for increasing the achievable diversity product. In this contribution, the MC DS-CDMA transmitter considered employs multiple Antenna Arrays (AA) and each of the AAs consists of several antenna elements. Furthermore, the proposed system employs both time- and frequency- (TF) domain spreading for extending the achievable capacity, when combined with a novel user-grouping technique for reducing the effects of Multiuser Interference (MUI). Moreover, in order to further enhance the system’s performance, we invoke a MultiLevel Coding (MLC) scheme, whose component codes are determined using the so-called equivalent capacity based constituent-code rate-calculation procedure invoking a 4-dimensional bit-to-SP-symbol mapping scheme. Our results demonstrate an approximately 3.8 dB Eb/N0 gain over an identical throughput scheme dispensing with SP modulation at a BER of 10?5

Performance analysis of multiple radio-access provision in a multicore-fibre optical fronthaul

[EN] In this work we report a comprehensive experimental study targeting the dimensioning of the next-generation multicore-fibre (MCF) optical fronthaul employing space-division multiplexing (SDM). This fronthaul is capable of simultaneous provision of multiple radio-access technologies (multi-RATs) with advanced multi-antenna MIMO capabilities per RAT. The different parameters required for fronthaul dimensioning are evaluated considering state-of-the-art 4G LTE-Advanced altogether other legacy wireless standards in operation nowadays. In particular, the modulation characteristics, the antenna quality requirements (in terms of EVM, phase error or rho) and the signal-to-noise ratio (SNR) thresholds are evaluated employing fully-standard cellular signals transmitted on a multicore fibre (MCF) fronthaul. The study includes bi-directional signal transmission and multi-antenna MIMO multiplexing. The MCF optical fronthaul is evaluated with a multiplexed transmission of 2G, 3G, 3.9G and 4G MIMO signals in radio-over-multicore-fibre (RoMCF) employing a commercially available four-core MCF. The SNR requirements at the transmitter antenna are obtained for each cellular signal considering GSM, EDGE, EGPRS2-A, cdma2000 1xEV-DO, UMTS HSPA+ and LTE-Advanced standards. LTE-Advanced singleantenna and two-antenna systems implementing 2 x 2 MIMO transmission can be accomplished with SNR levels over 25 dB. In the case of LTE-Advanced 4 x 4 MIMO multiplexing over four cores of MCF media, 32 dB SNR is needed to achieve almost four times provided bitrate per user.This research was supported in part by Spain National Plan MINECO/FEDER UE TEC2015-70858-C2-1-R XCORE and GVA AICO/2018/324 NXTIC projects. The work of M. Morant is supported by Spain Juan de la Cierva, Spain IJCI-2016-27578 grant and Fundacion BBVA Leonardo 2018 HYPERCONN project.Morant, M.; Llorente, R. (2019). Performance analysis of multiple radio-access provision in a multicore-fibre optical fronthaul. Optics Communications. 436:161-167. https://doi.org/10.1016/j.optcom.2018.11.036S16116743

Design And Analysis Of Cmos RFIC If Lowpass Filter 1.9GHz Range For CDMA Applications

This research sets out to design a completely integrated tunable low pass filter (LPF) with a bandwidth of 200 MHz utilizing Silterra 0.18μm submicron (SM) complementary metal oxide semiconductor (CMOS) technology. The application of this filter is narrowed down to perform as an IF filter in a superheterodyne receiver. Currently there are a few reported examples of this type of fully integrated CMOS filter. The main goals in the research will be to design and analyze the various types of filter architecture construction and choose one of the best of them to implement on integrated circuit layout base on their performance

SIMULATION OF A CODE DIVISION MULTIPLE ACCESS (CDMA) 2000 DOWNLINK SYSTEM

The topic chosen for this project is the simulation of a CDMA 2000 downlink system. CDMA 2000 is a 3G mobile telecommunications standard that uses CDMA to send voice, data and signaling data (such as a dialed telephone number) between mobile telephones and cell sites. The purpose of the simulation is to show that the design of the system can be implemented in actual application. The original codes and libraries aretaken directly from the Matlab software for the purpose of the simulation. The simulation is set up by considering the data rate, the channel model and also the performance of the system in terms of bit error rate results and the frame quality indicator. I

Technologies of Mobile Communication

Long-Term Evolution (LTE) is a new technology recently specified by 3GPP-Third Generation Partnership Project on the way towards fourth-generation mobile. This thesis presents the main technical features of this technology as well as its performances in terms of peak bit rate and average cell throughput, among others. LTE entails a big technological improvement as compared with the previous 3G standards. 1 However, this thesis also demonstrates that LTE performances do not fulfill the technical requirements established by ITU-R to classify one radio access technology as a member of the IMT-Advanced family of standards. Thus, this thesis describes the procedure followed by 3GPP to address these challenging requirements. Through the design and optimization of new radio access techniques and a further evolution of the system, 3GPP is laying down the foundations of the future LTE-Advanced standard, the 3GPP candidate for 4G

Performance measurements and analysis of the existing wireless communication technology in Iraq.

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel UniversityIraq may be considered as the largest wireless market in the Gulf region. A key driving factor in the market of wireless communication, it has seen enormous growth in the mobile phone market over the last five years leading to almost 24 million subscribers in 2011. Moreover, there are several technologies and services working in Iraq; three GSM Operators, three CDMA national operators and three CDMA provinces operators. The recent growth in the mobile phone market is based on the Global System for Mobile (GSM) communications and Code Division Multiple Access (CDMA) standards creating the next-generation wireless technologies in the Iraqi Wireless Communication market. One of the essential issues of this research is to investigate the performance of the decreased Quality Of Service (QoS) caused by interferences in the services on GSM/CDMA operators in Iraq. Many issues should be studied and taken into consideration, such as; does the Multi-Coalition Forces cause the interferences, jamming, higher rate of calls drop and false ringing; or are they caused by bad design and planning? Do we need to optimise our network due to the large number of users? All these factors are investigated and the measurements of most service providers and government agencies will be gathered. A detailed analysis was included from the providers with measurements of performance and the reasons for the deterioration of wireless services. The novel contributions of this thesis is the extensive radio measurement campaign over the three mobile an CDMA operator networks and the analysis and recommendations that were drawn to suggest the best approach to improve the QoS of Wireless communication technologies. Awareness of actual reasons behind the deterioration of services will be raised to the Iraqi Government, CMC and the wireless service providers