Title :
Differential detection of π/4-shifted-DQPSK for digital cellular radio
Author :
Chennakeshu, Sandeep ; Saulnier, Gary J.
Author_Institution :
General Electric Co., Schenectady, NY, USA
fDate :
2/1/1993 12:00:00 AM
Abstract :
The detection of π/4-shifted-DQPSK modulation using a tangent-type differential detector with an integrated symbol timing and carrier frequency offset correction algorithm is discussed. π/4-shifted-DQPSK modulation has been proposed for use in a high-capacity, TDMA-based digital cellular system being developed in the US; differential detection could potentially allow the production of low-complexity mobile units. Results obtained using the proposed IS-54 TDMA frame structure for base to mobile transmissions are presented. Theoretical and simulation bit-error-rate (BER) results are presented for static and Rayleigh fading channels. BER results are provided as a function of Eb/N0 and C/I, where the interferer is a second π/4-shifted-DQPSK signal. Additional results are provided which show the BER sensitivity to Doppler frequency shifts, time delay spread, and carrier frequency offsets
Keywords :
cellular radio; demodulation; digital radio systems; fading; phase shift keying; time division multiple access; π/4-shifted-DQPSK modulation; BER; Doppler frequency shifts; IS-54 TDMA frame structure; Rayleigh fading channels; bit-error-rate; carrier frequency offset correction; differential detection; digital cellular radio; integrated symbol timing; static fading channels; tangent-type differential detector; time delay spread; Bit error rate; Constellation diagram; Detectors; Digital modulation; Fading; Filters; Frequency; Land mobile radio cellular systems; Quadrature phase shift keying; Time division multiple access;
Journal_Title :
Vehicular Technology, IEEE Transactions on
