Distributed microcellular communications system

• US 5,809,422 A
• Filed: 03/08/1996
• Issued: 09/15/1998
• Est. Priority Date: 03/08/1996
• Status: Expired due to Term

• Current Assignee: Cisco Systems, Inc.
• Original Assignee: Watkins Johnson Co. (Qorvo, Inc.)
• Inventors: Raleigh, Gregory G., Pollack, Michael A.
• Primary Examiner(s): Chin, Tommy P.
• Assistant Examiner(s): Le, Vu
• Application Number:
  US08/611,600
• Time in Patent Office: 921 Days
• Field of Search: 455/449, 455/444, 455/447, 455/429, 455/443, 455/446, 455/450-453, 455/455, 455/509, 455/525, 455/561, 455/562
• US Class Current: 455/449
• CPC Class Codes: H04B 7/2609 Arrangements for range control, e.g. by using remote antennas
• CPC Class Codes: H04W 16/12 Fixed resource partitioning
• CPC Class Codes: H04W 16/24 Cell structures
• CPC Class Codes: H04W 16/32 Hierarchical cell structures
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

A distributed microcellular communication system comprised of a plurality of subcells arranged within one or more conventional cells. The distributed microcellular communications system includes one or more remote site stations, each of which transmits and receives information signals over an assigned set of communications channels within an associated subcell. Each remote site station includes a wideband RF receiver network within which information signals received from mobile units are converted into reverse link digital information signals. Also disposed within each remote site station is a remote communications link transceiver for transmitting the reverse link digital information signals over a communications link to the central base station, as well as for receiving forward link digital information signals from the central base station. The central base station includes a central communications link transceiver for receiving the reverse link digital information signals delivered over the communications link, as well as for transmitting the forward link digital information signals. The central base station is disposed to process the call information inherent within the forward and reverse link digital information signals in the manner required by standard cellular protocols. In an alternate implementation the remote site station further includes a channelizer for selecting a set of the reverse link digital information signals corresponding to the assigned set of communications channels, and may also include a bank of demodulator for demodulating the set of reverse link digital information signals.

Claims

1. A distributed microcellular communications system divided into a plurality of contiguous cells and for communicating with a plurality of mobile stations comprising:

a remote site station including;

a remote radio transceiver configured to communicate information signals with said mobile stations over an assigned set of communications channels within a first subcell within one of said cells;

(b) a converter configured to convert information signals received by said remote radio transceiver into reverse link information signals corresponding to said assigned set of communications channels;

(c) a remote link transceiver configured to transmit said reverse link information signals and to receive forward link information signals; and

(d) a channelizer configured to select a set of said reverse link information signals corresponding to said assigned set of communications channels; and

(e) wherein said remote link transceiver is configured to transmit said set of reverse link information signals corresponding to said assigned set of communications channels; and

a central base station having a central link transceiver and configured to receive said reverse link information signals from said remote site station and to transmit said forward link information signals to said remote site station.

2. The distributed microcellular communications system of claim 1 further comprising:

a controller configured to allocate said assigned set of communications channels from an available set of communications channels.

3. The distributed microcellular communications system of claim 1, further comprising:

a second remote site station including;

a second remote radio transceiver configured to communicate information signals with said mobile stations over a second assigned set of communications channels within a second subcell within said one of said cells;

(b) a second converter configured to convert information signals received by said remote radio transceiver to second reverse link information signals corresponding to said second assigned set of communication channels;

(c) a second remote link transceiver configured to transmit said second reverse link information signals and to receive second forward link information signals; and

(d) a second channelizer configured to select said reverse link information signals corresponding to said second assigned set of communications channels, and wherein said second remote transceiver is configured to transmit said second reverse link information signals corresponding to said second assigned set of communications channels; and

wherein said central link transceiver is configured to receive said second reverse link information signals from said second remote site station and to transmit said second forward link information signal to said second remote site station.

4. The distributed microcellular communications system of claim 3 further comprising:

a controller configured to allocate said assigned set of communications channels from an available set of communications channels and to allocate said second assigned set of communications channels from a second available set of communications channels.

5. The distributed microcellular communications system of claim 1 wherein maid remote site station further includes a multiplexer, interposed between said channelizer and said remote link transceiver and configured to multiplex said set of said reverse link information signals corresponding to said assigned set of communications channels into a reverse link said data stream.

6. The distributed microcellular communications system of claim 1 wherein said channelizer further includes a selector to select other ones of said reverse link information signals, said remote site station further including a signal quality monitoring module for monitoring signal quality of said communications channels corresponding to said other ones of said reverse link information signals.

7. The distributed microcellular communications system of claim 1 wherein said remote site station further includes:

a demodulator configured to demodulate said set of said reverse link information signals to produce a set of demodulated reverse link information signals; and

wherein said remote link transceiver is configured to transmit said set of demodulated reverse link information signals.

8. The distributed microcellular communications system of claim 7 wherein said remote site station father includes a plurality of beamformers disposed to receive said set of reverse link information signals, said demodulator including a corresponding plurality of demodulators coupled to said plurality of beamformers.

9. The distributed microcellular communications system of claim 1 wherein said remote site station further includes:

a modulator configured to modulate a carrier signal with said forward link information signals, thereby producing a plurality of modulated carrier signals; and

a translater configured to translate a frequency of said plurality of modulated carrier signals in order that each of said signal occupies an assigned frequency channel within a digitized forward link transmission spectrum.

10. The distributed microcellular communications system of claim 9 wherein said translator includes:

a plurality of digital transmitters each configured to modulate one of said carrier signals with one of said forward link information signals;

a digital to analog convertor; and

a digital summer interposed between said digital to analog converter and said plurality of digital transmitters.

11. The distributed microcellular communications system of claim 9 wherein said remote site station further includes a wideband transmitter configured to translate a frequency of said modulated carrier signals into a frequency-shifted forward link transmission spectrum.

12. The distributed microcellular communications system of claim 1 wherein said converter includes;

a wideband receiver for translating frequency of said information signals received by said transceiver to a frequency-shifted reverse channel spectrum, and

an analog to digital converter coupled to said wideband receiver.

13. In a cellular system including at least a first cell having a cell-site, a distributed microcellular communications system comprising:

a remote site station including;

(a) a wideband receiver for receiving reverse link information signals from users within a first subcell of said first cell, and for converting frequency of said reverse link information signals into a frequency-shifted reverse link spectrum so as to produce frequency-shifted reverse link information signals,

(b) an analog to digital converter for converting said frequency-shifted reverse link information signals into a plurality of reverse link digital information signals;

(c) a channelizer for selecting ones of said reverse link digital information signals corresponding to channel frequencies assigned to said remote site station, and

(d) a remote communications link transmitter for transmitting said reverse link digital information signals; and

a central base station, located at said cell-site, having a central communications link receiver for receiving said reverse link digital information signals.

14. The distributed microcellular communications system of claim 13 wherein said central base station further includes a central radio transceiver for transmitting and receiving information signals within a second subcell of said first cell, said communications system further including control means allocating selected ones of an available set of communications channels to said channel frequencies assigned to said remote site station and for allocating remaining ones of said available set of communications channels for use by said central radio transceiver.