Error-rate analysis for multirate DS-CDMA transmission schemes

VLSI Implementation of an Adaptive Multiuser Detector for Multirate WCDMA Systems

“…7 with 64 kbps (OVSF=16) and 16 users. In this figure, we observe that the raw BER of the adaptive signature receiver, Sign-MUD, attains 5% at an SNR of 6.5dB to outperform the Rake (16 2 14) Fixed point (16,2,14) Fixed point (14 2 12) Fixed-point (14,2,12) Fixed-point (13,2,11) 10 -1…”

“…Figure 5a illustrates the principle of the LRD adaptive signature receiver using FIR-LMS for the adaptation phase and FIR for the detection phase. Unlike the proposed works [12][13][14][15][16][17] that derived virtual signature codes, we consider real signature codes. More precisely, virtual users are generated for training sequences, r g 0 trainðnÞ k;v ðtÞ, as follows:…”

“…However, the dataflow complexity of VSF increases compared to MC method. Moreover, VSF systems actually offer the same performances in terms of bit error rate (BER) for low rate and high rate users in certain multirate communication scenarios [14].…”

“…Previous works on multirate multiuser detection rely on deriving an equivalent monorate system [12][13][14][15][16][17]. In fact, two well-known methods derive an equivalent monorate system based on the lowest data rate or highest data rate.…”

“…Two corresponding schemes are the so-called LRD adaptive signature MUD (LRD-Sign-MUD) and the HRD adaptive signature MUD (HRD-Sign-MUD), respectively. Unlike the existing works in [12][13][14][15][16][17] where virtual signature codes are generated depending on a multirate method, we consider real signature codes. In our work, moreover, virtual users are generated using real signature codes.…”