A high performance diversity selection technique for TDMA portable radio communications

The authors describe and show performance results for a diversity-selection technique in a frequency-selective fading portable radio channel. Diversity selection is performed by using a quality measure obtained from the demodulation process. This technique is compared to diversity selection based on power and diversity selection after channel decoding. It is found that this diversity selection technique is more effective in mitigating selective fading than a conventional technique based on power and that it performs almost as well as diversity selection after channel decoding. This diversity selection technique can be implemented at the portable handset by using only one receiver if the base station transmits in at least one time slot in addition to the communication slot. Thus, its use does not significantly increase the portable's hardware complexity. Simulations and experiments have confirmed that two-branch diversity using the proposed method can provide reliable speech communications using TDMA (time division multiple access) for a portable radio channel with RMS spread of 555 ns or less and a transmission rate of 450 kb/s.<<ETX>>

[1]  H. W. Arnold,et al.  A Hybrid Multichannel Hardware Simulator for Frequency-Selective Mobile Radio Paths , 1983, IEEE Trans. Commun..

[2]  D.M.J. Devasirvatham,et al.  Radio propagation studies in a small city for universal portable communications , 1988, 38th IEEE Vehicular Technology Conference.

[3]  Justin C.-I. Chuang.  The Effects of Time Delay Spread on Portable Radio Communications Channels with Digital Modulation , 1987, IEEE J. Sel. Areas Commun..

[4]  J.C.-I. Chuang,et al.  Outage probability for a frequency-selective fading digital portable radio channel with selection diversity using coding , 1989, IEEE International Conference on Communications, World Prosperity Through Communications,.

[5]  D. Devasirvatham.  A comparison of time delay spread and signal level measurements within two dissimilar office buildings , 1987 .

[6]  Justin C.-I. Chuang,et al.  Diversity selection using coding in a portable radio communications channel with frequency-selective fading , 1989, IEEE J. Sel. Areas Commun..

[7]  W. C. Jakes,et al.  Microwave Mobile Communications , 1974 .

[8]  Donald C. Cox,et al.  Universal Digital Portable Communications: A System Perspective , 1987, IEEE J. Sel. Areas Commun..

[9]  J.C.-I. Chuang,et al.  Burst coherent detection with robust frequency and timing estimation for portable radio communications , 1988, IEEE Global Telecommunications Conference and Exhibition. Communications for the Information Age.

[10]  Samy A. Mahmoud,et al.  A comparison of indoor radio propagation characteristics at 910 MHz and 1.75 GHz , 1989, IEEE J. Sel. Areas Commun..

[11]  J.C.-I. Chuang,et al.  Measured performance of 4-QAM with 2-branch selection diversity in frequency-selective fading using only one receiver , 1989, IEEE 39th Vehicular Technology Conference.

[12]  Nelson Ray Sollenberger,et al.  Architecture and implementation of an efficient and robust TDMA frame structure for digital portable communications , 1989, IEEE 39th Vehicular Technology Conference.

[13]  B. Glance,et al.  Frequency-Selective Fading Effects in Digital Mobile Radio with Diversity Combining , 1983, IEEE Trans. Commun..