Field experiments on TDMA mobile radio signal transmissions

Abstract

1-2356Take, Yokosuka-shi, Kanagawa-ken, 238-03 Japan.A B S T R U C T This paper describes a n experimental 1.45 GHz band T D M A signal transmission system. The system is characterized by T D M A structure with 3 time slots per carrier (combination of common access channel (CACH) and two traffic channels (TCH)), nnrrowband 1114-shift QPSK with differential detection, two-branch postdetection selection diversity reception, rate-213 and -112 block error correction to protect CACH data and associated control channel (ACCH) data, respectively, fast bit timing recovery for reception of CACH bursts at the base station and so on. T h e data rate for TCH is 8kbps and ACCH is multiplexed with TCH to form traffic burst flame. Laboratory experimental results on the bit error rate ( B E R ) performance for TCH data transmission due to additive white Gaussian noise ( A W G N ) , cochannel interference, and m u l t i p a t h channel delay spread are presented. Field experiments were also conducted in the Yokohama area to assess the BER performance in a real fading environment.

A 22 K Bd mobile video telephone scheme

“…The C1 BER turns out to be sufficiently low to be further reduced by FEC techniques, while the C2 BER is excessively high for image transmission. This prompted us to use 'fade-tracking' automatic gain control (AGC) [2] and second order diversity in line with other prototype systems [9]. The AGC requires 10% transmission overhead and both arrangements slightly increase the system's complexity at dramatic BER improvement.…”