contains documents related to adaptive beamforming algorithms for Wideband Code Division multiple access and a research article on circular patch antenna for C band altimeter system
problem of blind demodulation of multiuser
information symbols in a high-rate code-division multiple-access
(CDMA) network in the presence of both multiple-access interference
(MAI) and intersymbol interference (ISI) is considered.
ACPR (adjacent channel power ratio), AltCPR (alternatechannel power ratio), and noise are important performancemetrics for digital communication systems thatuse, for example, WCDMA (wideband code division multipleaccess) modulation. ACPR and AltCPR are bothmeasures of spectral regrowth. The power in the WCDMAcarrier is measured using a 5MHz measurement bandwidth;see Figure 1. In the case of ACPR, the total powerin a 3.84MHz bandwidth centered at 5MHz (the carrierspacing) away from the center of the outermost carrier ismeasured and compared to the carrier power. The resultis expressed in dBc. For AltCPR, the procedure is thesame, except we center the measurement 10MHz awayfrom the center of the outermost carrier.
In this project we analyze and design the minimum mean-square error (MMSE) multiuser receiver for uniformly quantized synchronous code division multiple access (CDMA) signals in additive white Gaussian noise (AWGN) channels.This project is mainly based on the representation of uniform quantizer by gain plus additive noise model. Based on this model, we derive the weight vector and the output signal-to-interference ratio (SIR) of the MMSE receiver. The effects of quantization on the MMSE receiver performance is characterized in a single parameter named 鈥漞quivalent noise variance鈥? The optimal quantizer stepsize which maximizes the MMSE receiver output SNR is also determined.
The first Third Generation Partnership Project (3GPP) Wideband Code Division
Multiple Access (WCDMA) networks were launched during 2002. By the end of 2005
there were 100 open WCDMA networks and a total of over 150 operators having
frequency licenses for WCDMA operation. Currently, the WCDMA networks are
deployedinUniversalMobileTelecommunicationsSystem(UMTS)bandaround2GHz
in Europe and Asia including Japan and Korea. WCDMA in America is deployed in the
existing 850 and 1900 spectrum allocations while the new 3G band at 1700/2100 is
expected to be available in the near future. 3GPP has defined the WCDMA operation
also for several additional bands, which are expected to be taken into use during the
coming years.
Since the principle of multi-carrier code division multiple access (MC-CDMA) was
simultaneously proposed by Khaled Fazel et al. and Nathan Yee et al. at the IEEE
International Symposium on Personal, Indoor and Mobile Radio Communications
(PIMRC) in the year 1993, multi-carrier spread spectrum (MC-SS) has rapidly become
one of the most wide spread independent research topics on the field of mobile radio
communications. Therefore, the International Workshop on Multi-Carrier Spread
Spectrum (MC-SS) was initiated in the year 1997. Multi-carrier and spread spectrum
systems with their generic air interface and adaptive technologies are considered as
potential candidates to fulfill the requirements of next generation mobile communications
systems.
The continuing vitality of spread-spectrum communication systems and the devel-
opment of new mathematical methods for their analysis provided the motivation to
undertake this new edition of the book. This edition is intended to enable readers
to understand the current state-of-the-art in this field. Almost twenty percent of the
materialinthiseditionisnew, includingseveralnewsections, anewchapteronadap-
tive arrays and filters, and a new chapter on code-division multiple-access networks.
The continuing vitality of spread-spectrum communication systems and the devel-
opment of new mathematical methods for their analysis provided the motivation to
undertake this new edition of the book. This edition is intended to enable readers
to understand the current state-of-the-art in this field. Almost twenty percent of the
materialinthiseditionisnew, includingseveralnewsections, anewchapteronadap-
tive arrays and filters, and a new chapter on code-division multiple-access networks.
The remainder of the material has been thoroughly revised, and I have removed a
considerable amount of material that has been superseded by more definitive results.
