Title :
Influence of system load on channel estimation in MC-CDMA mobile radio communication systems
Author :
Sälzer, Thomas ; Mottier, David ; Brunel, Loïc
Author_Institution :
Mitsubishi Electr. ITE, Rennes, France
Abstract :
This paper investigates the influence of a variable system load on the performance of the channel estimation in a multicarrier code division multiple access (MC-CDMA) transmission scheme. We consider channel estimation based on pilot symbols, which are periodically inserted into the MC-CDMA frame. Starting from the analytical expression of the decision variable, we show the impact of erroneous channel estimation as a function of system load. We derive a simple adaptation rule for the pilot symbol power in order to maintain the signal-to-noise ratio (SNR) loss due to channel estimation errors constant for all system loads. We show that this simple rule enables us to minimize the total transmitted power required at a given bit error rate (BER), particularly for systems with high spreading gain as used in mobile radio channels with high frequency diversity
Keywords :
code division multiple access; diversity reception; error statistics; mobile radio; parameter estimation; spread spectrum communication; time-varying channels; BER; MC-CDMA mobile radio communication systems; SNR; adaptation rule; bit error rate; channel estimation; decision variable; frequency diversity; mobile radio channels; multicarrier code division multiple access transmission scheme; pilot symbols; signal-to-noise ratio loss; spreading gain; system load; variable system load; Bit error rate; Channel estimation; Computer simulation; Frequency diversity; Interference cancellation; Land mobile radio; Multiaccess communication; Multicarrier code division multiple access; OFDM; Signal to noise ratio;
Conference_Titel :
Vehicular Technology Conference, 2001. VTC 2001 Spring. IEEE VTS 53rd
Conference_Location :
Rhodes
Print_ISBN :
0-7803-6728-6
DOI :
10.1109/VETECS.2001.944897
