FULL DUPLEX WIRELESS COMMUNICATION SYSTEM WITH SINGLE MASTER CLOCK

Abstract

A base station and the customer premises equipment (CPE) transceivers are configured to use a single master clock for all frequency conversions. The modem of each CPE has a clock output and that output is connected to the upconverter in the transceiver uplink or to both the upconverter and the downconverter as required.

Claims

1) A wireless communication system comprising a base station and a plurality of customer premises equipment, each of said customer premises equipment comprising a transceiver with a downlink and an uplink, each of said uplink and downlink being connected between a modem and an antenna, said modem comprising a clock output, said clock output being connected to said uplink in a manner to synchronize or slave a local clock in said upconverter.

2) A wireless communication system as in claim 1 wherein said modem clock output is connected to said downlink in a manner to synchronize or slave a local clock in said downconverter.

3) A transceiver comprising an upconverter with an external clock input.

4) A transceiver as in claim 3 comprising a downconverter with an external clock input.

5) A modem with both a data and a clock output.

6) Customer premises equipment comprising a transceiver, said transceiver comprising an upconverter with an external clock input and a modem with both a data and clock output.

7) A full duplex wireless communication system, said system comprising a plurality of transceivers, said transceivers being characterized by the absence of local clocks.

8) A wireless base station for a wireless communication system, said base station comprising an uplink connected between an antenna and a CMTS, said CMTS comprising a master clock output, said clock output being connected electrically to said uplink at a point between said downconverter and said CMTS.

9) A base station as in claim 8 also including an upconverter in the downlink, said clock output being connected electrically to said downlink at a point between said upconverter and said CMTS.

10) A base station as in claim 8 comprising a UHF transceiver with a downconverter, said CMTS clock output being connected to said uplink in a manner to impose said master clock on said downconverter.

11) A full duplex wireless communication system with a single master clock for all frequency conversions.

12) Customer premises equipment comprising an upconverter in the absence of an operative local clock and a modem with both a data and clock output.

13) Customer premises equipment in accordance with claim 12 comprising a downconverter in the absence of an operative local clock.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG. 1 is a generic block diagram of prior art UHF base station and customer premises equipment (CPE);

[0018] FIG. 2 is a block diagram of a prior art cable modem;

[0019] FIG. 3 is a cable modem in accordance with this invention;

[0020] FIG. 4 is a block diagram of prior art UHF transceiver;

[0021] FIG. 5 is a block diagram of a UHF transceiver in accordance with this invention;

[0022] FIG. 6 is a block diagram of prior art S-Band transceiver;

[0023] FIG. 7 is a block diagram of an S-Band transceiver in accordance with this invention;

[0024] FIG. 8 a block diagram of a UHF Band base station in accordance with this invention;

[0025] FIG. 9 a block diagram of a prior art S-Band base station;

[0026] FIG. 10 is a block diagram of an S-Band base station in accordance with this invention.

DETAILED DESCRIPTION

[0027] FIG. 1 shows a prior art the base station including a tower 10 and a base station 12 along with a representative CPE. The base station includes CMTS 22 and downconverter 19. The CPE comprises an antenna 17, a cable modem 14 and a transceiver 15.

[0028] FIG. 2 shows a prior art cable modem 20 with RF link port 21 and data ports 24.

[0029] FIG. 3 shows a UHF Band cable modem 20a in accordance with this invention. The cable modem can be seen to include a master clock output indicated at number 41.

[0030] Each CPE of a wireless system includes a transceiver. FIG. 4 shows a prior art transceiver 45 connected between an antenna 46 and a cable modem 47, respectively. The transceiver includes a downlink 50 and an uplink 51. Uplink 51 includes an upconverter 53. The transceiver uplink and downlink include additional components as is well understood. These components are not shown herein because they are not changed in any way in accordance with this invention.

[0031] A UHF transceiver 60, in accordance with this invention, is represented in FIG. 5. Transceiver 60 is connected to cable modem 61 with a master clock output 63. Output 63 is connected to clock input port 67a on upconverter 67 located in uplink 65 in a manner to synchronize (or slave) the local oscillator in the upconverter 67.

[0032] The prior art S-Band transceiver 70 of FIG. 6, (compare with FIG. 4) shows a downconverter 71 in downlink 72 in addition to an upconverter (74).

[0033] FIG. 7. shows an S-Band transceiver 80 in accordance with the present invention, the transceiver includes downlink 82 and uplink 83. The downlink and the uplink include downconverter 84 and upconverter 85, respectively. Importantly, the S-Band transceiver of FIG. 7 includes the cable modem 87 of FIG. 3 with the master clock output 88 of the modem connected to clock input 84a on downconverter 84 and clock input 85a on upconverter 85 by conductor 86.

[0034] FIG. 8 shows the configuration of the base station 90 for UHF Band operation. Here the uplink is shown to include downconverter 91 connected to the CMTS 92. In this embodiment of the invention, the CMTS may be reconfigured to comprise a clock output 92a that is connected to clock input port 99a on downconverter 99.

[0035] A comparison of FIG. 9 with FIG. 10 illustrates that the prior art S-Band base station 100 does not include a master clock connection between the CMTS 103 and the upconverter 106 and downconverter 109. The S-band base station in accordance with this invention shown in FIG. 10 has a master clock output 220 on CMTS 203 that is connected to clock input 206a on upconverter 206 and to clock input 205a on downconverter 205.

[0036] It is important to understand that, in accordance with the present invention, the modem is reconfigured to provide a clock output and for UHF Band operation, the modem clock output is connected only to the upconverter as shown in FIG. 5. For an S-Band transceiver, the modem clock output is connected to both the upconverter and to the downconverter as shown in FIG. 7. Also, the connection point for the clock to the downconverter and the upconverter need only be along the downlink and the uplink such that the (master) clock from the modem is controlling any local clocks that are either synchronized with the master or slaved. The downconverters and the upconverts thus could be configured in the absence of local clocks.

[0037] The foregoing description relates to the base station and to CPEs and the inclusion of a reconfigured modem and the connection of a (master) clock. In the base station, the CMTS may provide the master clock to the downconverter in the UHF Band base station as shown in FIG. 8 and to both the downconverter and the upconverter for the S-Band base stations as shown in FIG. 10.

[0038] Since every CMTS has associated modems, the CMTS at the base station can be configured to connect to a local modem (see FIG. 3) that provided a master clock output that connects to the upconverter and downconverter as required at the base station for S-Band and UHF-Band operation in accordance with the invention where there is no master clock output on the CMTS.

[0039] What has been described herein is considered merely illustrative of the principles of this invention. Thus, it should be understood that those skilled in the art may be capable of producing modification thereof within the scope of the claims.

[0040] For example, anyone skilled in the art will understand that the base station includes a cable modem termination system could equally well directly provide the (master) MC on it output and that clock source could be designed to take an external input reference clock source and synchronize it Master Clock (MC) to the external input clock source. In this way, one could still use the external input reference clock source to which the upconverter and the downconverter would synchronize. Overall mechanism of using a single MC for the complete WBS would still be maintained.