Title :
The effect of low SNR in phase estimation in wideband CDMA
Author :
Quirk, Kevin J. ; Milstein, Laurence B.
Author_Institution :
Dept. of Electr. & Comput. Eng., California Univ., San Diego, La Jolla, CA, USA
fDate :
1/1/2001 12:00:00 AM
Abstract :
In wideband code-division multiple-access (CDMA) systems, where large diversity gains are used to mitigate the effects of multipath fading, system performance is increasingly limited by channel estimation error. In a packet-based system, the estimation error can be reduced by increasing the header length; however this, for a fixed bandwidth, reduces the amount of transmit energy available to the data symbols and reduces the processing gain of the system. To determine the allocation of the transmit energy between the data and estimation symbols in order to minimize the probability of bit error, we use an approximate upper bound on the probability of bit error for a RAKE receiver operating with imperfect phase estimates
Keywords :
broadband networks; code division multiple access; diversity reception; error statistics; fading channels; multipath channels; multiuser channels; noise; packet radio networks; phase estimation; radio receivers; spread spectrum communication; RAKE receiver; approximate upper bound; bandwidth; bit error probability; channel estimation error; code division multiple access; data symbols; estimation error; estimation symbols; header length; imperfect phase estimates; large diversity gain; low SNR; multipath fading; packet-based system; phase estimation; processing gain; spread spectrum communication; system performance; transmit energy allocation; wideband CDMA systems; Bandwidth; Channel estimation; Diversity methods; Estimation error; Fading; Multiaccess communication; Phase estimation; System performance; Upper bound; Wideband;
Journal_Title :
Selected Areas in Communications, IEEE Journal on
