Title :
Performance of compensation algorithms for direct-conversion receivers under finite wordlength constraints
Author :
Weber, R. ; Jordan, Mariana ; Christoffers, N. ; Muller, H.-C.
Author_Institution :
Hella KGaA Hueck & CO., Lippstadt
Abstract :
Direct-conversion receivers have attracted increased attention recently as they represent an interesting architecture in portable wireless environments, where power, cost, and size are critical design constraints. They suffer, however, from various front-end impairments, with I/Q imbalance, DC offset, and flicker noise being among the most serious ones. Digital compensation algorithms have been proposed in the literature to cope with the adverse effects. Usually, these algorithms are analyzed by computer simulations in nearly infinitely precise arithmetic. A fixed-point finite wordlength implementation on DSPs, FPGAs, and ASICs typically results in a reduced performance. This paper investigates the performance degradation of various compensation algorithms due to a finite wordlength. The results obtained by bit-true simulations demonstrate that a moderate wordlength is sufficient to achieve results similar to infinite precision
Keywords :
application specific integrated circuits; field programmable gate arrays; fixed point arithmetic; flicker noise; radio receivers; roundoff errors; ASIC; DC offset; DSP; FPGA; I-Q imbalance; application specific integrated circuit; digital compensation algorithm; digital signal processing; direct-conversion receiver; field programmable gate array; fixed-point finite wordlength implementation; flicker noise; front-end impairment; portable wireless environment; 1f noise; Band pass filters; Computer simulation; Costs; Digital arithmetic; Frequency; Local oscillators; Passive filters; Signal design; Signal processing algorithms;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 2005. PIMRC 2005. IEEE 16th International Symposium on
Conference_Location :
Berlin
Print_ISBN :
9.7838007291e+012
DOI :
10.1109/PIMRC.2005.1651865