Title :
Frequency-hopping versus interference cancellation for TD-CDMA
Author :
Correia, Américo M C ; Rodrigues, António C B ; Cercas, Francisco António Bucho
Author_Institution :
Dept. of Electr. & Comput. Eng., Inst. Superior Tecnico, Lisbon, Portugal
Abstract :
This work considers asynchronous time division code division multiple access (TD-CDMA) systems with RAKE receivers and one stage of parallel interference cancellation (PIC) or serial interference cancellation (SIC). A general method based on the concept of spherically symmetric signals is presented for the evaluation of the average probability of error of uncoded TD-CDMA systems. Slow frequency-hopping (SFH) with frequency overlap (FO) between adjacent carriers and interference cancellation are also included in the analysis, which considers the multipath Rayleigh fading channel (which models indoor and outdoor vehicular radio propagation). We analyze quadrature phase shift keying (QPSK) modulation with coherent demodulation and multipath (frequency) diversity with maximal ratio combining (MRC). Power control, adaptive SFH, and interference cancellation are employed for improving the bit-error rate (BER) performance. It is found that the scheme with SFH, in spite of the FO, always improves the performance substantially, and interference cancellation, in general, provides the highest BER improvement.
Keywords :
Rayleigh channels; adaptive systems; cellular radio; code division multiple access; demodulation; diversity reception; error statistics; frequency hop communication; indoor radio; interference suppression; multipath channels; multiuser channels; power control; quadrature phase shift keying; radio receivers; radiofrequency interference; telecommunication control; time division multiple access; BER performance; GSM; QPSK; RAKE receivers; UMTS; adaptive SFH; adjacent carriers; asynchronous time division code division multiple access; average error probability; bit-error rate; coherent demodulation; frequency diversity; frequency overlap; indoor radio propagation; maximal ratio combining; multipath Rayleigh fading channel; multipath diversity; outdoor vehicular radio propagation; parallel interference cancellation; performance; power control; quadrature phase shift keying; serial interference cancellation; slow frequency-hopping; spherically symmetric signals; uncoded TD-CDMA systems; Bit error rate; Diversity reception; Fading; Frequency; Interference cancellation; Multiaccess communication; Multipath channels; Power system modeling; Quadrature phase shift keying; Silicon carbide;
Journal_Title :
Selected Areas in Communications, IEEE Journal on
