The objective of this study is to present our views on key topics with respect to third generation 3G and address some of the more technical aspects of the CDMA 3G proposal.
India 1 aasheeshshukla yahoo. Few of them are in application while others are under development for future application. IMT has published a set of requirements for 3G radio interfaces and criteria for evaluating candidate radio interfaces against these requirements.
These proposals cover both terrestrial and satellite networks. These two proposals may become the dominant 3G standards . In this paper, we analyze the basic principals of these multiple access schemes.
So, this paper is organized as follows: First, CDMA is introduced and its major features are presented. CDMA provides two deployment options. One of them is a Multi-Carrier configuration where available bandwidth is divided into N 1.
The user data is demultiplexed and spread on to N separate channels. The Multi-Carrier option is supported only in the forward direction. The other deployment Electronic copy available at: We will discuss these features of CDMA in following points 2.
CDMA uses a base spreading rate of 1.
The spreading rates are 1. The value on N can be 1, 3, 6, 9 and The spreading rates are multiple of 1. Timing and phase information is derived by the receivers from the pilot signal, which helps in coherent demodulation of other code channels.
CDMA employs a common pilot channel in the forward direction that is shared by all mobiles. This pilot channel is a code multiplexed channel using Walsh codes for orthogonal spreading. CDMA Pilot channels 2. Synchronous operation means the transmission and reception timings of cell sites are synchronized.
However, dependence on a common source for synchronization can result in a single point of failure. The loss of that source may make entire system unavailable for service.
Common channels are point to multipoint channels between the base station and multiple mobile stations used in shared access mode. The pilot, sync, paging and access channels are common channels derived from ISB.
In addition to these channels, CDMA defines the common control channel. The Common control channel has been Electronic copy available at: Cell sites of CDMA Dedicated channels are point to point channels between the base station and a single mobile station carrying information dedicated to a single user.
In addition to these channels, CDMA defines a dedicated control channel. It carries upper layer signaling, MAC signaling and short user bursts.
The dedicated control channel has several purposes. First, it can carry short user bursts for data services.
Secondly, it can be used in association with the fundamental channels to carry signaling and power control information.
This allows the fundamental channel to carry only voice information, thus providing high quality voice services. It is a radio interface of choice for UMTS. W-CDMA supports asynchronous mode of operation where reception and transmission timings of different cell sites are not synchronized. It supports fast cell acquisition when a mobile initially powers up.
It also supports forward and reverse fast closed loop power control operation. W-CDMA uses a base spreading rate of 4.
The spreading rates are 4. The value on N can be 1, 2 and 4.So, in this paper an overview of CDMA, W-CDMA, and IDMA is presented and also discuss the main features and areas of application as the future air interface access schemes for IMT/UMTS.
Keywords: Multiple Access, WCDMA, IDMA, Interleaver. WHITE PAPER: This paper outlines a step-by-step approach to developing a unified enterprise mobility strategy, enabling a more cost-effective and efficient delivery of network connectivity to a larger mobile workforce.
GSM and CDMA are the most successful cell phone technologies present in world, CDMA handsets are chip based where as GSM handsets uses SIM cards, using the GPRS and EDGE facility GSM is successful to Lure the customers but CDMA is still behind GSM due to its limited obesity and other problems.
Research papers cdma - put out a little time and money to receive the paper you could not even dream about Leave your assignments to the most talented writers. Order the needed paper here and put aside your worries. MHz MHz Fig. 2: Deployment scenario for CDMA and WCDMA in a 2x 15 MHz operation Guard a r WCDMA 1 MHz MHz MHz MHz Guard 5 MHz 5 MHz Fig.
3: Deployment scenario for CDMA and WCDMA in a 2x 20 MHz operation debated . Free research papers, free research paper samples and free example research projects on CDMA topics are plagiarized. schwenkreis.com is professional research paper writing service which is committed to write top-quality custom research papers, term papers, essays, thesis papers and dissertations.