Title :
Turbo equalisation for the Enhanced GPRS system
Author_Institution :
Nokia Res. Center, Espoo, Finland
Abstract :
The iterative receiver structures can often improve the performance with a reasonable level of complexity. We study an iterative equalisation technique, i.e., turbo equalisation (TE), which enables to improve the performance by signal processing means in the receiver-without altering any other part of the system. TE is based on the feedback information from the channel decoder into the equaliser. That information is used as a priori information in the equaliser to start a new iteration, which provides more reliable decisions. The performance evaluation for Enhanced General Packet Radio System (EGPRS) shows that TE is beneficial for 8-PSK modulation in particular giving a 2 dB gain with one extra iteration. However, TE requires a soft-in-soft-out (SISO) decoder to be used, since the feedback information from the decoder should contain reliability information
Keywords :
Rayleigh channels; cellular radio; decision feedback equalisers; iterative methods; minimum shift keying; multipath channels; packet radio networks; phase shift keying; radio receivers; sequential estimation; turbo codes; 8-PSK modulation; DFE; DFSE; EGPRS; Enhanced GPRS system; Enhanced General Packet Radio System; GMSK; GSM; SISO decoder; a priori information; channel decoder; convolutional code; decision feedback equaliser; decision feedback sequence estimation; feedback information; iterative equalisation; iterative receiver structures; multipath transmission channel; performance evaluation; reliability information; signal processing; soft-in-soft-out decoder; turbo equalisation; Additive white noise; Decision feedback equalizers; Fading; GSM; Ground penetrating radar; Iterative decoding; Maximum likelihood decoding; Maximum likelihood estimation; Speech analysis; Tellurium;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 2000. PIMRC 2000. The 11th IEEE International Symposium on
Conference_Location :
London
Print_ISBN :
0-7803-6463-5
DOI :
10.1109/PIMRC.2000.881551
