Handset detector architectures for DS-CDMA wireless systems

Abstract

This paper investigates detector architectures for wireless handsets employing DS-CDMA. The code-matched filter (MF) and minimum output energy (MOE) detectors are analyzed with respect to fixed-point arithmetic behavior. Architectures employing fixed-point arithmetic are then proposed for these detectors. The maximum throughput of these architectures and the associated costs in terms of area usage and power consumption are evaluated. Results of the fixed-point analysis indicate that the MOE detector is more susceptible to quantization than the MF detector. Results of implementation indicate that the superior performance of the MOE detector is achieved at a considerably higher cost in terms of area usage and power consumption. Finally, comparison of hardware implementation with softwarebased DSP implementation indicates that software approaches result in considerably lower throughputs.

A Rapid Prototyping Environment for Wireless Communication Embedded Systems

“…Methods in [10,11,12] demonstrate significant performance improvements. In addition, the application of fixedpoint techniques [13] to the equations trade a small decrease in accuracy for a significant performance increase.…”

“…Moving to the design of the blind MMSE detector block, Figures 14 and 15 show the application of appropriatelanguage design discussed in Section 4, in which an MMSE detector written in C [13] is "wrapped" into a Simulink block. Figure 14 shows the Wrapper's GUI which is used to specify the type and size of the input ports, output ports, and parameters, similar to the FIR filter's d, f, taps, and filterCoeffs shown in Figure 10.…”

Spreading and power allocation for multiple antenna transmission using decorrelating receivers

“…However, we feel that with improved very large scale integration (VLSI) architectures simple decorrelating detectors can be easily implemented in the mobile handset. Tradeoffs between complexity and performance of various single user and multiuser detector architectures in the mobile handset are investigated in [10]. one antenna is used.…”

“…For analytical exposition, we use the throughput expression assuming the noises are independent. Since independent bits are transmitted through the two antennas, the throughput of the system is given by the sum of two respective BSC throughputs with crossover probabilities of and and can be expressed as (9) If the fading processes are identically distributed, the throughput can be simplified as (10) We plot the throughput for the single-antenna, STD, and MPS in Fig. 3(a) for five users using Gold codes of length 31.…”

Untitled

“…Finally, comparison of hardware implementation with software-based DSP implementation indicates that software approaches result in considerably lower throughputs. [15] The MF and MOE detector architectures were implemented on a Xilinx Virtex XCV800 FPGA and a TI 'C6x DSP using a length 31 Gold spreading code. The Virtex power estimator was used to estimate the power consumption of the FPGA for both architectures.…”