AU763248B2

AU763248B2 - Serial type frequency conversion repeater in radio frequency communication system

Info

Publication number: AU763248B2
Application number: AU58366/99A
Authority: AU
Inventors: Don Shin Lee
Original assignee: HIGH GAIN ANTENNA CO Ltd
Current assignee: HIGH GAIN ANTENNA CO Ltd
Priority date: 1999-08-31
Filing date: 1999-11-08
Publication date: 2003-07-17
Anticipated expiration: 2019-11-08
Also published as: KR100331786B1; KR20010019849A; AU5836699A

Description

r/uu 1 1 28/5/91 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT

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Application Number: Lodged: Invention Title: SERIAL TYPE FREQUENCY CONVERSION REPEATER IN RADIO FREQUENCY COMMUNICATION SYSTEM

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The following statement is a full description of this invention, including the best method of performing it known to us I -1 a, 1 SERIAL TYPE FREQUENCY CONVERSION REPEATER IN RADIO FREQUENCY COMMUNICATION SYSTEM

BACKGROUND

Technical Field The present invention relates to a repeater which relays forward and backward service signals by converting frequency of the signals to a permitted *oo.

frequency band but unused for a service, in which the signal is used between a S.mobile communication base station and subscriber terminals.

The present invention converts the frequency of relay signal used by a link repeater and a service repeater, for transmitting/receiving forward and backward service signals between the base station and the subscriber terminals.

Therefore, the present invention particularly relates to a serial type frequency conversion repeater capable of high-powered relay from the base station to the 15 service repeater where is far from the base station, by simultaneously processing frequency converting service and link repeating operation between the base station and the subscriber terminals by using new relay signal separated from the relay signal.

Background The present invention is an improvement on KR Patent No. 144,208 titled as "high power repeater for a mobile communication system". The patent provides a relay service having a good communication quality, by which the high power repeater relays signals to new frequency by frequency conversions, in case that a mobile terminal goes into an area where is not provided for a service. In addition, it has solved problems of vibrating and crosstalk caused by that the conventional repeater output is returned to input thereof, and of low output caused by poor intermodulation characteristic.

However, with the structure of the above-mentioned system in which the repeater in installed with the base station in parallel, it requires additional base stations in the case of the communication with the remote subscriber terminal being located at, for example, several tens to hundreds km away from it, resulting in higher installation cost.

SUMMARY

Accordingly, in order to solve the problems in the prior art it is an object of the present invention to provide a serial type frequency conversion repeater ee••e capable of high-powered relay from a base station to a subscriber terminal s15 where is far from the base station, by simultaneously processing frequency converting service and link repeating operation by converting frequency of new relay signal used between a link repeater and a service repeater, for transmitting/receiving forward and backward service signals between the base station and the subscriber terminal.

One embodiment to accomplish the object of the present invention provides a serial type frequency conversion repeater including a link repeater and a service repeater for relaying forward or backward signals between a base station and subscriber terminals, by converting frequency of the forward service signals(TF1, TF3, TFn) or the backward service signals(RF1, RF3, RFn) to frequency of forward or backward relay signals (Tf2, Tf4, Tfm)(Rf2, Rf4, Rfm) in a permitted frequency band but unused for a service, in which the forward service signals are transmitted from the base station to the subscriber terminals and the backward service signals are transmitted from the subscriber terminals to the base station, wherein the repeater includes frequency converting service and link repeating means for; receiving forward or backward relay signals (Tf2, Tf4, Tfm)(Rf2, Rf4, Rfm) which are not used for actual service between the link repeater and the service repeater, dividing the received signals to two parts, repeating one signal of two parts to service signals (TF1, TF3, TFn)(RF1, RF3, RFn) between the base station and the subscriber terminals, transmitting the repeated signal to a serving subscriber terminal, converting another signal of two parts to relay signals (tf21, tf41, tfp)(rf21, rf41, rfp) in another frequency band different from the relay signals (Tf21, Tf41, tfm)(Rf2, Rf4, Rfm), and transmitting the converted relay signals (tf21, tf41, tfp)(rf21, rf41, rfp).

Particularly, the present invention provides the serial type frequency conversion repeater, in which the repeater includes at least two frequency converting service and link repeater serially interconnected for relaying serial signals according to the distance. Here, the repeater according to the present invention is that a plurality of repeating units are serially interconnected with only a single base station resulting in lower installation cost not for adding another base station and in easiness for adding another repeater.

And the present invention provides the serial type frequency conversion repeater which converts to frequency of relay signals (tf21, tfp)(rf21, e* *lo

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rf41, rfp) in a permitted frequency band but unused for a service and carries out the frequency conversion by each frequency converting service and link repeater by using a single frequency band, for preventing the crosstalk and interference effect which may be generated among relay signals.

BRIEF DESCRIPTION Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawing, in which: FIG. 1 shows overall configuration serial type frequency conversion repeater according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS S"Embodiment of the invention will be described with reference to drawing.

S. 15 FIG. 1 shows overall configuration of the serial type frequency conversion repeater according to the present invention. Referring to FIG. 1, only one repeating unit 300 is shown for simplicity of the explanation. Other repeating units are same if there is any. Now it will be explained with the repeater having a repeating unit.

Referring to FIG. 1, the serial type frequency conversion repeater includes a link repeater 200 and a service repeater 400 between a base station 100 and subscriber terminals for converting service signals(TF1, TF3, TFn)(RF1, RF3, RFn) to relay signals(Tf2, Tf4, Tfm)(Rf2, Rf4, Rfm) which are in a permitted frequency band but unused for a service, and vice versa.

And the serial type frequency conversion repeater includes a repeating unit 300 using a new relay signal in another frequency band different from the frequency band used by the link repeater 200 and the service repeater 400, with high power for a long distance. The repeating unit 300 includes a first frequency converting service and link repeater 310 and a second frequency converting service and link repeater 330.

The repeaters 310, 330 are serially interconnected, and the repeating unit 300 can include more than two repeaters depending upon the distance to S 10 the subscriber terminal. The longer the distance is, the more repeaters in the repeating unit 300.

The first/second frequency converting service and link repeaters 310, 330 receive forward or backward relay signals(Tf2, Tf4, Tfm)(Rf2, Rf4, Rfm) transmitted between the link repeater 200 and the service repeater 400 "15 but unused for an actual service and divide the relay signals into 2 parts(or may divide into more than One of the parts is repeated to the service signals(TF1, TF3, TFn)(RF1, RF3, RFn) between the base station and subscriber terminal and then relayed to the subscriber terminal in a serving area. The other part transmitted/received between the first/second frequency converting service and link repeaters 310, 330, is converted into relay signals(tf21, tf41, tfp)(rf21, rf41, rfp) in another frequency band. The repeaters 310, 330 are serially interconnected, and the repeating unit 300 can include more than two repeaters depending upon the distance to the subscriber terminal.

The first frequency converting service and link repeater 310 and the second frequency converting service and link repeater 330, have same configuration, respectively. And the respective frequency converting service and link repeaters 310, 330 have duplexers at both ends for both transmission and reception about forward service signals. And there are a low noise amplifier, an N frequency divider, a narrow IF amplifier, an N coupler, and a high power amplifier between the two duplexers for forward signals. Additionally, for backward signals, the elements are the same.

The frequency converting service and link repeaters 310, 330 use the relay signals(tf21, tf41, tfp)(rf21, rf41, rfp) in different frequency band which to is permitted frequency band but unused for a service, i. different from the forward or backward relay signals(Tf2, Tf4, Tfm)(Rf2, Rf4, Rfm) used by the link repeater 200 and the service repeater 400.

The frequency converting service and link repeaters 310, 330 predetermine each frequency conversion band to a constant band, such that the 15 base station selects the single constant band among the frequency bands for serving to a subscriber terminal.

The serial type frequency conversion repeater as constructed above will be explained how to operate.

The service signals(TF1, TF3, TFn)(RF1, RF3, RFn) transmitted from the base station 100 via the link repeater 200 and transmitted from the subscriber terminal via the service repeater 400 for serving analog and digital mobile communications(GSM, TDM, CDMA, etc.), are converted to the relay signals(Tf2, Tf4, Tfm)(Rf2, Rf4, Rfm) in the permitted frequency band but unused for a service in the link repeater 200 and the service repeater 400, and then transmitted to the repeating unit 300 located several tens km away from the repeaters 200, 400.

The frequency converting service and link repeaters 310, 330 divide the received relay signals(Tf2, Tf4, Tfm)(Rf2, Rf4, Rfm) from the link repeater 200 or the service repeater 400 into two signals. One of the divided two signals is repeated to the service signals(TF1, TF3, TFn)(RF1, RF3, RFn) between the base station and the subscriber terminal, the repeated signals are amplified with high power, and then the respective amplified signals are transmitted to service available subscriber terminal. And the other signals are converted to S 10 other relay signals(tf21, tf41, tfp)(rf21, rf41, rfp) in a permitted frequency band but unused for a service different from the relay signals(Tf2, Tf4, Tfm)(Rf2, Rf4, Rfm), amplified with high power, and then transmitted to the other frequency converting service and link repeater. For example, the first frequency converting service and link repeater 310 transmits the relay 15 signals(tf21, tf41, tfp)(rf21, rf41, rfp) to the second frequency converting service and link repeater 330. And the second frequency converting service and link repeater 330 transmits the relay signals(tf21, tf41, tfp)(rf21, rf41, rfp) to the first frequency converting service and link repeater 310. As described above, the repeaters 310, 330 transmit and receive the signals from each other, which locate separately with the distance of several tens km.

Accordingly, the repeating unit 300 positioned between the link repeater 200 and the service repeater 400 receives the signals transmitted between the link repeater 200 and the service repeater 400 and then divides the received signals to two. The repeating unit 300 repeats one of two signals, amplifies the repeated signal with high power, and then transmits the amplified signals to service available subscriber terminal. The repeating unit 300 also converts the other signals to other relay signals different from the relay signals of the link repeater 200 and the service repeater 400, amplifies the converted signals with high power, and then transmits the amplified signals to the service repeater 400 or the link repeater 200.

The frequency converting service and link repeaters 310, 330 use the relay signals(tf21, tf41, tfp)(rf21, rf41, rfp) in the permitted frequency band but unused for a service, in which the relay signals(tf21, tf41, tfp)(rf21, rf41,.., rfp) in the other frequency band is different from the forward or backward relay signals(Tf2, Tf4, Tfm)(Rf2, Rf4, Rfm) used by the link repeaters and the service repeaters. Thereby it is capable of avoiding interference effect by an antenna feedback, as well as serving the high powered signal process between the base station and the subscriber terminal.

15 The frequency converting service and link repeaters 310, 330 predetermine each of frequency conversion band to a constant band, thereby the base station assign the single constant band among the frequency bands serving to a subscriber terminal. Assigning a predetermined frequency band to each of repeaters, the channel utilization is more efficient.

As described above, the two-way communication is performed between the base station 100 and subscriber terminals 110, 320, 340, 410. In the serial type frequency conversion repeater according to the present invention, it is easy to add other repeaters if needed in order to extend service distance.

In the conventional way, the repeater is installed with the base station in parallel for a long distance communication system. However, the serial type frequency conversion repeater according to the present invention is that a plurality of repeating units are serially interconnected with only a single base station resulting in lower installation cost not for adding another base station and in easiness for adding other repeaters.

Besides, with this manner of frequency conversion into another permitted frequency band, the interference with the antenna feedback is avoided.

The present invention is not limited to the specifically disclosed embodiments, and variations and modifications may be made without departing from the scope of the present invention.

Claims

1. Serial type frequency conversion repeater including a link repeater and a service repeater for relaying forward or backward signals between a base station and subscriber terminals, by converting frequency of the forward service signals (TF1, TF3, TFn) or the backward service signals (RF1, RF3, RFn) to frequency of forward or backward relay signals (Tf2, Tf4, Tfm)(Rf2, Rf4, Rfm) in a permitted frequency band but unused for a service, in which the forward service signals are transmitted from the base station to the subscriber terminals and the backward service signals are transmitted from the subscriber terminals to the base station, wherein the repeater includes frequency converting service and link repeating means for; receiving forward or backward relay signals (Tf2, Tf4, Tfm)(Rf2, Rf4,.. Rfm) which are not used for actual service between the link repeater and the service repeater, dividing the received signals to N parts, repeating one signal of the parts to service signals (TF1, TF3, TFn)(RF1, RF3, RFn) between the base station and the subscriber terminals, transmitting the repeated signal to a serving subscriber terminal, converting another signal of the parts to relay signals (tf21, tf41, tfp)(rf21, rf41, rfp) in another frequency band different from the relay signals (Tf21, Tf41, Tfm)(Rf2, Rf4, Rfm), and transmitting the converted relay signals (tf21, tf41, tfp)(rf21, rf41, rfp).

2. Serial type frequency conversion repeater as claimed in claim 1, wherein the repeater includes at least two said frequency converting service and link repeaters serially interconnected.

3. Serial type frequency conversion repeater as claimed in claim 1, wherein the frequency band of relay signals (tf21, tf41, tfp)(rf21, rf41, rfp) different from the relay signals (Tf2, Tf4, Tfm)(Rf2, Rf4, Rfm) is in a permitted frequency band but unused for a service. a 11

4. Serial type frequency conversion repeater as claimed in claim 1, wherein the relay signals (tf21, tf41, tfp)(rf21, rf41, rfp) in the another frequency band different from the relay signals (Tf2, Tf4, Tfm)(Rf2, Rf4, Rfm) are used by predetermining a single frequency ban among the frequency bands transmitted from the base station to subscriber terminals. Serial type frequency conversion repeater substantially as hereinbefore described with reference to Figure 1. DATED this 23rd day of May 2003 HIGH GAIN ANTENNA CO. LTD WATERMARK PATENT TRADE MARK ATTORNEYS 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRALIA MCQ/MAP/TLS e o**