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US 6,151,484 AGranted
Communications apparatus and methods for adaptive signal processing based on mobility characteristics
AssigneeEricsson Inc.
InventorRajaram Ramesh
Life of this patent
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AssigneeEricsson Inc.
InventorRajaram Ramesh
Estimating the term…
Information represented by a signal generated in a communications medium by a first entity is recovered by receiving the signal from the communications medium at a second entity, determining a mobility characteristic for communications between the first entity and the second entity, and adaptively estimating the information from the received signal based on the determined mobility characteristic. The mobility characteristic may be received from the first entity at the second entity, and the information represented by the received signal may be adaptively estimated based on the received mobility characteristic. According to an embodiment of the invention, the mobility characteristic is a cell type identifier which is communicated from a base station to a mobile terminal, the mobile terminal adaptively estimating information from a signal received from the base station based on the communicated cell type identifier. A number of signal processing functions may be adaptively performed, including adaptive demodulation, adaptive channel estimation/interpolation, adaptive equalization, adaptive channel tracking, and adaptive combining of received signals.
A communications system, comprising:
A communications system, comprising:
A cellular communications system, comprising:
A communications terminal, comprising:
A method of recovering information represented by a signal generated in a communications medium by a first entity, the signal representing information including a symbol sequence including a pilot symbol, the method comprising the steps of:
A method of communicating information between a mobile terminal and a base station which serves a cell of a cellular communications system, the method comprising the steps of:
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
By interpolation between sounding signals: by non-linear interpolation
Radio transmission systems, i.e. using radiation field: control of transmission; Equalising
Digital communication
Transmission
Term ended 8 Aug 2017 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to communications systems and methods, in particular, to systems and methods for recovering information from signals generated in a communications medium.
Radiotelephone systems are commonly employed to provide voice and data communications to a plurality of mobile units or subscribers. For example, analog cellular radiotelephone systems, such as designated AMPS, ETACS, NMT-450, and NMT-900, have been deployed successfully throughout the world. More recently, digital cellular radiotelephone systems such as designated IS-54B in North America and the pan-European GSM system have been introduced. These systems, and others, are described, for example, in the book titled Cellular Radio Systems by Balston, et al., published by Artech House, Norwood, Mass., 1993.
As illustrated in FIG. 1, a conventional cellular communication system 20 includes one or more mobile terminals 10 which can communicate with one or more base stations 20 serving cells 30. The base stations 20 are connected to a mobile telephone switching office (MTSO) 40, which may in turn be connected to a public switched telephone network 50. Although only two cells 20 are shown in FIG. 1, a typical cellular network may include hundreds of base stations, thousands of mobile terminals and more than one MTSO. Each cell will have allocated to it one or more dedicated control channels and one or more voice channels. Through this cellular infrastructure, a communication link may be effected between two mobile terminals 10, or between a mobile terminal 10 and a landline telephone 60, with a base station 20 typically functioning as a relay station for data and voice information.
Some of the objects and advantages of the present invention having been stated, others will be more fully understood from the detailed description that follows and by reference to the accompanying drawings in which:
FIG. 1 is a schematic diagram illustrating a conventional cellular communications system;
FIGS. 2-3 are schematic diagrams illustrating embodiments of a cellular communications system according to the present invention;
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, like numbers refer to like elements throughout.
For purposes of the discussion herein, "estimation of information" from a signal refers generally to those operations commonly known as "signal estimation" or "signal processing" in which information is extracted from an electromagnetic signal used to represent the information, including, but not limited to, operations such as demodulation, filtering, sampling, equalizing and the like. In addition, "mobility characteristic" as referred to herein includes information relating to spatio-temporal relationships which may impact on communications between entities of a communications system. For example, in a cellular communications system in which mobile terminals communicate with base stations which serve geographical cells, a mobility characteristic may include information relating to spatial-temporal relationships between base stations and mobile terminals, such as speed or range of a specific mobile terminal or typical speed and range characteristics of a population of mobile terminals within a cell with respect to a base station serving the cell. The present invention arises from the realization that due to the effect these mobility characteristics can have on signal properties, e.g., delay spread, more optimal estimation of information from a signal received from a communications medium, e.g., more optimal signal processing, may be achieved by adaptively tailoring signal processing architectures and parameters to varying mobility characteristics.
FIG. 2 provides an illustration of a cellular communication system according to the present invention, including a base station 210 which includes means for generating a signal 215 in a communications medium, for example, a transmitter 202 generating a signal through a transmit antenna 204. A mobile terminal 220 includes signal receiving means including, for example, a receive antenna 222, for receiving the generated signal 215. The received signal 223 is processed by adaptive estimating means 224 included in the mobile terminal 220, based on a mobility characteristic 227 determined by mobility characteristic determining means 226. As illustrated in FIG. 3, the roles of the base station 210 and the mobile terminal 220 may be reversed, with the base station 210 including signal receiving means, e.g, a base station antenna 212 and associated hardware, for receiving a signal 211 generated by the mobile terminal 220. Information 215 is adaptively estimated from the received signal 213 by adaptive estimating means 214, based on a mobility characteristic 217 determined by mobility characteristic determining means 216 included in the base station 210.