상세정보
학술지
A One-Shot LDD with Pre-SDC/Post-MRC for Random CDMA Over Asynchronous Rayleigh Channels
- 발행일
- 200202
- 출처
- IEEE Journal on Selected Areas in Communications, v.20 no.2, pp.257-263
- ISSN
- 0733-8716
- 출판사
- IEEE
- 협약과제
- 01MR5400, W-CDMA 방식 IMT-2000용 다수 사용자 검출 기술 연구, 김성락
- 초록
- It is well known that conventional detectors of direct sequence-code division multiple access systems are interference-limited; Multiuser detection has been considered as a promising approach to combat this problem. Since an optimal multiuser detector is too complex to implement, several suboptimal multiuser detector techniques have been developed. The one-shot linear decorrelating detector (LDD) was proposed to reduce the computational complexity and delay required in the conventional LDD, but it still require high complexity. Another one-shot LDD with low complexity was proposed. To improve its performance, this detector uses a maximal ratio combining (MRC) at the two outputs of the left piece of the present bit and the right piece of the next bit in an one-shot window; hereafter this detector is called as a one-shot LDD with post. MRC. In spite of the aid of MRC, the performance of the one-shot LDD with post. MRC is worse than the one-shot LDD. To overcome this problem, we propose the one-shot LDD with pre-SDC/post-MRC that employs selection diversity combining (SDC) with multiple antenna elements in the front of the one-shot LDD with post. MRC. In asynchronous random code division multiple access systems over fading channels, the largest signal-to-noise ratio (SNR) of SDC, near-far resistance (NFR) of the one-shot LDD, and the output SNR of MRC are random variables. We derive the probability density functions (PDFs) for these random variables and calculate the bit error rate) of the proposed detector using the obtained PDFs. In comparison of mathematical analysis and computer simulation results, we observe good agreement.
- KSP 제안 키워드
- Bit Error Rate(And BER), Code division Multiple Access(CDMA), Computational complexity, Computer simulation(MC and MD), Direct-sequence(DS), Maximal-ratio-combining(MRC), Multiuser detection, Output SNR, Probability Density Function, Random code, Random variable