Communications: directive radio wave systems and devices (e.g. – Directive – Utilizing correlation techniques
Patent
1999-02-18
2000-07-25
Hellner, Mark
Communications: directive radio wave systems and devices (e.g.,
Directive
Utilizing correlation techniques
342378, G01S 1316
Patent
active
060941677
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
Our present invention relates to a process for the directionally resolved reception of digital data by a phase-controlled group antenna which is provided with a circuit with which the directional characteristic of the group antenna is adjustable and adaptable in accordance with the to adaptive effect of antenna weighting factors in the interconnection of the individual antennas, whereby for the adjustment and adaptation of the directional characteristic a decision feedback process is used in which a nonlinear structure is provided comprised of a forward filter, a backward filter and a decision circuit, whereby the antenna signals are fed initially to the forward filter, then to the decision circuit, and from the decision circuit to the backward filter, whereupon the output signal of the backward filter is subtracted from the output signal of the forward filter. The invention relates further to a device for the directionally resolved reception of digital data in which a phase-controlled group antenna is provided and the group antenna has a circuit with which the directional characteristic of the group antenna is adjustable and adaptable in accordance with the adaptive effect of antenna weighting factors in the interconnection of the individual antennas, whereby for the adjustment and adaptation of the directional characteristic a nonlinear structure is provided comprised of a forward filter, a backward filter and a decision circuit, whereby the individual antennas are connected to the inputs of the forward filter, the output of the forward filter is connected to a subtractor whose output is connected to the input of the decision circuit which has its output connected to the input of the backward filter, the output of which is connected to the second input of the subtractor.
STATE OF THE ART
Directionally resolved reception is a promising new technique for increasing the range, reducing the common-channel is interference and thereby reducing the frequency repetition spacing in mobile communications.
The increase in the range is of interest in lightly settled regions and also for large umbrella cells in which overflow traffic from subordinate microcells must be absorbed. A further interesting field of application is radio access for fixed network subscribers ("radio in the local loop", RLL, or "radio in the loop", RITL).
The common channel interference is known to be the limiting influencing factor for well developed cellular mobile radio networks.
Directionally resolved reception, in which a maximum of the directional diagram of the receiving antenna is in the incident direction of the desired signal (of a subscriber) and/or zero locations of this directional diagram lie in incident direction of interference signals, reduces the common channel interference. These interference signals are, for example, signals which either derive from other subscribers in the same cell or from subscribers in foreign (distal) cells. With this mode of operation it is possible to so reduce the frequency repetition spacing that in an extreme case, reuse of the same frequency is possible in a neighboring cell (channel group number equal to one). With the processes proposed to date for the directionally resolved reception, the lower limit of the angular separation at which the process breaks down is a significant problem. In the ideal case this lower limit should be 0.degree..
A process or a device of the type described at the outset is known from EP 604 956. According to this document, a signal at the output of the decision circuit is used as a data signal, that means that it should correspond with the transmitted signal. The problem here is that this signal is fed back to the input of the decision circuit via the backwards filter. Should a decision error arise, a false signal is then applied at the input of the decision circuit which can give rises to further decision errors. With considerable interference, for example in the case of mobile telephones in neighboring cells, the data signal is thus very o
REFERENCES:
patent: 4255791 (1981-03-01), Martin
patent: 4717919 (1988-01-01), Cherrette et al.
patent: 4780721 (1988-10-01), Dobson
patent: 5579016 (1996-11-01), Wolcott et al.
patent: 5608409 (1997-03-01), Rilling
"Adaptive Antennas for Mobile Communications" E&CEJL, GB, Bd. 6, #4, Aug. 94, pp. 203-214, M. Barrett, R. Arnott.
T. Bull, M. Barrett, R. Arnott, "Technology in Smart Antennas for Universal Advanced Mobile Infrastructure (TSUNAMIR2108) --Overview".
Proc. Race Mobile Telecom. Summit, Cascais, Prt. Nov. 22-24, 1995, pp. 88-97.
Bonek Ernst
Fuhl Josef
Dubno Herbert
Hellner Mark
Telekom Austria Aktiengesellshaft
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