A two-layer spreading code scheme for dual-rate DS-CDMA systems
نویسندگان
چکیده
This letter considers multiuser detection in variable-spreading-length multi-rate direct-sequence code-division multiple-access systems. A two-layer spreading (TLS) code scheme is proposed which facilitates the low-complexity adaptive implementation of linear minimum mean-square error multiuser receivers in a dual-rate system. It is demonstrated via large system analysis and simulation that imposing a TLS structure does not incur loss in terms of the output signal-to-interference ratio performance.
منابع مشابه
Throughput Improvement of STS-Based MC DS-CDMA System with Variable Spreading Factor
The throughput enhancement of Space-Time Spreading (STS)-based Multicarrier Direct Sequence Code Division Multiple Access (MC DS-CDMA) system is investigated in this paper. Variable Spreading Factor (VSF) is utilized to improve the data throughput of the system. In this contribution, an analytical approach is proposed to compute a new expression for the Bit Error Rate (BER) performance of t...
متن کاملA Novel Complex-Modulation Based Space-Time Spreading Scheme with More Than Two Transmit Antennas for MC-DS-CDMA Systems
–Space-time spreading (STS) is a promising scheme combining the ubiquitously employed code division multiple access (CDMA) with the emerging space-time block coding (STBC) technique. Almost all research results reported so far mainly focus on the STS schemes based on the full-rate STBC, which use either only two transmit antennas or real-modulations. However, the complex-modulation based STS sy...
متن کاملBit Error Performance for Asynchronous Ds Cdma Systems Over Multipath Rayleigh Fading Channels (RESEARCH NOTE)
In recent years, there has been considerable interest in the use of CDMA in mobile communications. Bit error rate is one of the most important parameters in the evaluation of CDMA systems. In this paper, we develop a technique to find an accurate approximation to the probability of bit error for asynchronous direct–sequence code division multiple–access (DS/CDMA) systems by modeling the multipl...
متن کاملOptimum near-far resistance for dual-rate DS/CDMA signals: Random signature sequence analysis
Optimum near-far resistance is studied for synchronous dual-rate DS/CDMA systems. Three multi-rate access schemes are considered: multi-code (MC) access where high-rate users multiplex their data bits onto multiple codes and form a single-rate system ; variable spreading length (VSL) access where the spreading lengths of signature sequences are inversely proportional to users' data rates; and v...
متن کاملBlind channel estimation in multi-rate multicarrier DS-CDMA systems
Multi-rate multicarrier DS-CDMA is a potentially attractive multiple access method for future broadband wireless multimedia networks that must support integrated voice/data traffic. This paper proposes a subspace based channel estimation scheme for multi-rate multicarrier DS-CDMA, which is applicable to both multicode and variable spreading factor systems. The performances of the proposed schem...
متن کاملذخیره 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 ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- IEEE Trans. Communications
دوره 51 شماره
صفحات -
تاریخ انتشار 2003