Exploiting Data Correlation to Reduce the Power Variance for Forward-link CDMA Sequences

نویسنده

  • R. Neil Braithwaite
چکیده

This paper investigates the effect of interactions between the Walsh codes and data sequences on the statistical moments of the forward-link CDMA signal. Of primary interest is the normalized fourth-order moment, which is referred to as the “power variance”. Several techniques for reducing the power variance of the CDMA signal are discussed that are based on Walsh code selection and data encoding. Results illustrate the effects of data correlation, and demonstrate the reduction in the power variance afforded by two novel approaches referred to as “channel hopping” and “data bit reversal”. IEEE keywords: multi-access communication, intermodulation distortion.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Performance Analysis of ZF Pre-Coder and Extended Joint Channel Estimation Method in Downlink CDMA with HPA

In the down link scenario of code division multiple access (CDMA) systems, multi user detectors (MUDs) such as linear de-correlating detector (LDDs) provide satisfactory symbol error rates (SERs) at the expense of much increased complexity, they require all active users’ spreading sequences, which is impractical from privacy point of view. To overcome this impracticality, a simple matched filte...

متن کامل

Iterative Construction of Spreading Sequences in CDMA Forward Link

In this paper, we consider an iterative algorithm to construct spreading sequences in a CDMA forward link to support users with a uniform target signal-to-interference ratio (SIR). Particular attention is given to the case when the number of users is larger than the spreading gain. We classify users into two classes, namely, overfaded users and nonoverfaded users, according to their effective n...

متن کامل

Non - Orthogonal Forward Link for Future Cdma Cellular Systems

In this thesis we propose the use of non-orthogonal forward link for future CDMA cellular systenis. The non-orthogonal forward lin& uses long PN codes as the spreading codes. The use of long PN codes has a few advantages over the common practice of using orthogonal codes. It ailows the design of a flexible air interface that can easily accommodate multimedia traffic, and has the potential to of...

متن کامل

Joint transmitter-receiver adaptive forward-link DS-CDMA system

Abstract— A joint transmitter-receiver adaptive DS-CDMA system over a slow flat fading forward-link channel is considered in this paper. A set of spreading sequences is designed to support all users with a uniform target SIR. This set of sequences reduces to the optimum solution of the transmitter optimization problem of choosing a set of sequences to meet the SIR target with a minimum total tr...

متن کامل

Forward-link capacity of a DS/CDMA system with mixed multirate sources

Some studies have been done on capacity of a code division multiple access (CDMA) system with mixed multirate sources. However, a vast majority of these studies have concentrated on the reverse link. This trend comes from the fact that the capacity of a CDMA system is reverse-link limited. However, forward link can be a limiting link because emerging data services are likely to require higher d...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1999