A multicarrier trellis-coded eight-phase shift keying (8-PSK) system using a frequency hopping (FH) technique is proposed to improve bit-error rate (BER) performance in digital land mobile communications. In general, a trellis-coded modulation (TCM) system is employed with interleaving in multipath fading environment; by contrast, in the proposed system, an FH technique is employed to disperse the influence of successively received weak signals due to multipath fading with small delay, i.e., without interleaving process. The BER performances of the proposed system are investigated by computer simulation. It is found that, although there is no improvement in diversity order by applying the FH technique, there is an improvement in energy efficiency as compared with a multicarrier trellis-coded 8-PSK system in a Rayleigh fading channel. It is also found that the performance of the proposed system is not affected by the fade rate of the channels, i.e., the proposed system is effective even under slow fading conditions. It is shown that the performance of the proposed system is affected by the number of hopping frequency; moreover, there is an optimum number of hopping frequency, which depends on the span of dominant error event path of the multiple trellis code employed. Therefore, it is found that the proposed system is effective in the case in which the processing delay time is restricted, such as mobile speech communications.
|ジャーナル||Electronics and Communications in Japan, Part I: Communications (English translation of Denshi Tsushin Gakkai Ronbunshi)|
|出版ステータス||Published - 1996 12月|
ASJC Scopus subject areas
- コンピュータ ネットワークおよび通信