A Set of Cyclic Orthogonal Codes Acquired from Walsh-Hadamard Matrix

نویسنده

  • Jamshid Abouei
چکیده

In this paper, the properties of the WalshHadamard codes used as spreading codes in QCDMA cellular systems are analyzed. It is shown that among Walsh-Hadamard codes, obtained from Hadamard Matrix , only k 2 ) , 2 ( k H k 1 + k codes are orthogonal to each other in all phases. Also, the performance of the Walsh Hadamard codes is compared with that of the Gold codes from the average cross-correlation points of view. Index: Spread spectrum, Walsh Hadamard codes, Gold codes, cross-correlation

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

Design of Logic Network for Generating Sequency Ordered Hadamard Matrix H

A logic network to produce the sequency ordered Hadamard matrix H based on the property of gray code and orthogonal group codes is developed. The network uses a counter to generate Rademacher function such that the output of H will be in sequency. A general purpose shift register with output logic is used to establish a sequence of period P corresponding to a given value of order m of the Hadam...

متن کامل

Providing Higher Throughput for a Single User with M-ary Orthogonal Walsh Codes

Reliable communication is a challenge in a very noisy RF channel further corrupted by severe, multiple narrowband interference. Code Division Multiple Access (CDMA) is a widely used method to both mitigate such interference and support multiple in-band users. The ability to time-control multiple receptions at a receiver permits use of deterministically orthogonal codes. Achieving full capacity ...

متن کامل

Iterative Decoding withM -ary Orthogonal Walsh Modulation in OFDM-CDMA Systems

Iterative decoding of a serial concatenated coding scheme consisting of an outer convolutional code and M -ary orthogonal Walsh modulation as inner Walsh-Hadamard block code in an OFDM-CDMA system is applied. New aspects arise because OFDM enables the iterative decoding structure to exploit time as well as frequency diversity of a mobile channel. Moreover, the paper points out the low complex s...

متن کامل

The MAI performance of orthogonal codes for channel cover in Asynchronous CDMA system

It is widely believed that the walsh code is the best to provide covering for a CDMA channel due to its orthogonality. However, it exhibits a severe aperiodic ACF and variation of its aperiodic ACF pattern for each code. Hence, the comparison of MAI performances of walsh sequences with other three orthogonal sequences as a channel cover code in DS-CDMA was established. The aperiodic ACF and CCF...

متن کامل

On Walsh code assignment

Abstract-The paper considers the problem of orthogonal variable spreading Walsh-code assignments. The aim of the paper is to give assignments that can avoid both complicated signaling from the BS to the users and blind rate and code detection amongst a great number of possible codes. The assignments considered here use a partition of all users into several pools. Each pool can use its own codes...

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 2007