Title :
Performance Analysis of Direct-Sequence Impulse Radio With RAKE Reception in Frequency-Selective Channels
Author_Institution :
Dept. of Inf., Electron. & Telecommun., Univ. of Rome La Sapienza, Rome, Italy
fDate :
3/1/2011 12:00:00 AM
Abstract :
An ultrawideband (UWB) format that jointly utilizes direct-sequence (DS) and time-hopping (TH) spreading, which is called direct-sequence impulse radio (DS-IR), is analyzed. A simple and widely applicable expression for the symbol error rate (SER) of a multiuser DS-IR system that operates over a frequency-selective channel with RAKE reception and quadrature phase-shift keying (QPSK) modulation is presented, based on the well-known simplified improved Gaussian approximation. The SER expression is next used in conjunction with a quasianalytical SER estimation to analyze the performance of DS-IR over the IEEE 802.15.4a channel, focusing on the impact of the TH and the system duty cycle on the SER. It is shown that the duty cycle can be varied with a minor effect on the SER if TH is exploited. On the other hand, when TH is suppressed, low-duty systems suffer an increase in SER, which, depending on the system parameters, can range from dramatic to negligible.
Keywords :
Gaussian processes; Zigbee; error statistics; quadrature phase shift keying; radio receivers; ultra wideband communication; IEEE 802.15.4 channel; QPSK modulation; RAKE reception; UWB format; direct-sequence impulse radio; duty cycle; frequency-selective channels; improved Gaussian approximation; multiuser DS-IR system; quadrature phase-shift keying modulation; quasianalytical SER estimation; symbol error rate; time-hopping spreading; ultrawideband format; Impulse radio (IR); RAKE reception; ultrawideband (UWB);
Journal_Title :
Vehicular Technology, IEEE Transactions on
DOI :
10.1109/TVT.2011.2107335