Spread-spectrum changeable base station

SWEDEN (12) PATENT WRITING (13) C2 (11) 522 690

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(19) SE (51)

International class ⁷

H04J 13/02, H04B 7/216

PATENT AND REGISTRATION (45) (41) (22) (24) (62) (86) (86) (83)

Patent filed Application widely available The patent application was submitted on expiration date

National application number International filing date Filing date for European patent application Deposit of microorganism

2004-02-24

2002-12-13

2002-10-23

1995-06-16

9604710-5

1995-06-16 (21) Patent Application Number 0203118-5

Application received as:

Swedish patent application completed international patent application with number PCT / US95 / 08561 converted European patent application with number (30)

1994-06-29 US 268186 (73) (72) (74) (54) (56) (57)

PATENT HOLDER Interdigital Technology Corp., 913 Market Street, Wilmington DE 19801 US

INVENTOR Donald L Schilling, Sands Point NY US

OMBUD AWAPÄTENT AB

NAME Basic sub-unit for use in a wireless broadband communication system

CALLED PUBLICATIONS: - - SUMMARY:

A conference call bandwidth communication system

Suite 802 uses a plurality of spreaders, any of which can act as the base station and where the base station can be changed upon request. Each spreading unit comprises a base subunit (11-21), a remote subunit (40), and a command subunit (41-44). An operator can initiate a command signal from the command subunit (41-44) to activate the base subunit (11-21). Accordingly, the command signal is transmitted to the plurality of spread-spectrum units after initialization of the command signal. At each remote subunit (40), in each spreading unit, the command signal is received, and in response to receiving the command signal, the remote subunit (40) is activated.

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Base station

AöST

The numbers in brackets indicate international identification code, INID code. Letters in clamps indicate international document code.

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SUMMARY

A conference call bandwidth communication system uses a plurality of bandwidth units, any of which can act as the base station and where the base station can be changed upon request. Each spreading unit comprises a base subunit (11-21), a remote subunit (40), and a command subunit (41-44). An operator can initiate a command signal from the command subunit (41-44) to activate the base subunit (11-21). Accordingly, the command signal is transmitted to the plurality of spread-spectrum units after initialization of the command signal. At each remote subunit (40), in each spreading unit, the command signal is received, and in response to receiving the command signal, the remote subunit (40) is activated.

Publishing image = fig 1

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Background of the invention

The present invention relates to a base subunit for use in a wireless spread-spectrum communication system.

Description of prior art

Bandwidth modulation is a well-developed technique, in terms of generating chipping sequences, and spreading processing data signals with the hacking sequences. By using this technique, communication links can be established at a transmitter and receiver at remote locations. In addition, networks can be established through the use of a conference call broadcast technology. Conference call tape spreading techniques are disclosed in U.S. Patent No. 5,179,572 entitled SPREAD SPECTRUM CONFERENCE CALLING SYSTEM AND METHOD, to Schilling, and in U.S. Patent No. 5,263,045 entitled SPREAD SPECTRUM CONFERENCE CALL SYSTEM AND METHOD, to Schilling.

A problem may exist where a spread-spectrum conference call system is set up, but the base station may need to be changed. For example, in a military environment, a pluton can use spread-spectrum modulation for conference calls among the members of the pluton. A specific unit of the platoon can be designated as a base station. Said prior art does not describe how a base station should be switched from one pluton to another or what would happen among units of the pluton in the event that such a change is necessary.

Summary of the Invention

A general object of the present invention is a conference call band spread communication system where the base station can be changed upon request.

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Another object of the present invention is a spread-spectrum conference calling technique where any unit can act as a base station.

In accordance with the present invention, according to this embodiment and description, a spreading system is provided which has a plurality of spreading units. Each spreading unit has the capacity to operate as a base station and as a remote station. Each spreading unit comprises a base subunit, a remote subunit, and a command subunit.

The present invention comprises receiving, at a first frequency, in the base subunit a plurality of spreading signals transmitted from the plurality of spreading signals transmitted from the plurality of spreading units. The multiple band spread signals are despread and demodulated in the base sub-unit to generate a plurality of demodulated signals. The multiple demodulated signals are combined, and a local signal, such as a data signal or a voice signal from the user of the device, is also combined to generate a combined signal. The base subunit converts the combined signal into a base data signal. The base sub-band spreads out the base data signal, and, using radio waves, transmits the spread-spread base data signal at a second frequency as a base band spread signal.

At each of the spread spectrum units, in the respective remote subunit, the baseband spread signal is received at the second frequency. The remote subunit includes circuits for spreading the baseband spread signal, and demodulation of the scattered baseband spread signal into a base analog signal. The remote subunit may also take the local voice signal, referred to herein as a remote analog signal, and convert the remote analog signal into a remote data signal. The remote subdivision bandwidth processes the remote data signal and transmits the remote data 5222 690 signal at the first frequency as one of the plurality of broadband signals.

An operator can initiate a command signal from the command subunit to activate the base subunit. Actually, following command 5, the command signal is transmitted to the plurality of spread-spectrum units after initiation of the command signal. At each of the spreading units, in the respective remote subunit, the command signal is received, and in response to receiving the command signal, the remote subunit is activated.

Further objects and advantages of the present invention are set forth in part in the following description, and are partly obvious from the description, or may be obtained by practicing the present invention.

The objects and advantages of the present invention can also be realized and achieved by the means and combinations specifically pointed out in the appended claims.

Brief description of the drawings

The accompanying drawings, which are included in and form part of the specification, illustrate preferred embodiments of the present invention, and together with the description, serve to explain the principles of the invention.

Fig. 1 is a block diagram of a base subunit;

Figure 2 is a block diagram of a remote subassembly;

and Fig. 3 is a block diagram of a command subunit. Detailed description of the preferred embodiments

Reference is now made in detail to the present preferred embodiments of the present invention, examples of which are shown in the accompanying drawings, in which like reference numerals indicate like elements in all views.

The present invention provides a unique solution to the problem of a plurality of bandwidth devices used in a mobile environment where any of the

522 The 690 spreading units are sensitive to neutralization while maintaining communication between all the spreading units remains of great importance. The spread-spectrum changeable base station is applicable in a platoon of units, in an army environment, or in a police application, where a portable base station can be set up to control a plurality of spread-spectrum remote units. The problem of focusing on each of these applications is what happens when the base unit becomes unusable or stops working. In the military environment, the base station can be destroyed. In a police situation, the mobility of the multiple spreading units may require the base station to be changed from one unit to another.

The spreading system has a plurality of spreading units, each spreading unit having a base subunit, a remote subunit and a command subunit. The use of the term subunits to designate the base subunit, the remote subunit and the command subunit is intended to describe the present invention. The present invention may be constructed as a fully integrated unit, or as a blend assembly of more than one unit.

The base subunit is shown in Figure 1. The base subunit includes a receiving means, a despreading means, a demodulating means, a combining means, a conversion means, a spreading processing means, and a transmitting means. The spreading means is connected between the receiving means and the demodulating means. The combination means is coupled to the demodulation means and the conversion means. The band spreading means is coupled to the conversion means and the transmission means.

The receiving means is shown in Fig. 1 as antenna 11 which is coupled to radio frequency / intermediate frequency amplifier and filter section (RF / RF amplifier and filter section) 12. The scattering means is shown as a plurality of mixers.

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13, 14, 15. Each of the plurality of mixers 13, 14, 15 has a respective chopping sequence gi (t), g2 (t) ..., g ^ j (t), for mixing with the received spread spread signal. The majority of chopping sequences are matched with the chopping sequence of the desired spread spread signal to be dispelled.

The demodulator and combiner are shown as demodulator 16 and combiner 17A, 17B. The combiners 17A, 17B may be a single combiner performing the combining function, or separate combiners. The conversion means is shown as an analog-to-digital converter 18. The band-spreading processing means is shown as product device 19, which has a hacking sequence for spreading the data signal from analog-to-digital converter 18.

The transmitting means is shown as transmitter 20 and antenna 21.

The RF / IF amplifier and filter circuits 12 are coupled to the antenna 11 and to the plurality of mixers 13, 14,

15th The plurality of mixers 13, 14, 15 are coupled to demodulator 16 and combiners 17A, 17B. The analog-to-digital converter 18 is coupled to combiner 17B and to product device 19. Transmitter 20 is coupled to product device 19 and to antenna 21. Antenna 21 and antenna 11 may be the same antenna with suitable isolation circuits, or different antennas.

The RF / IF amplifier and filter circuits 12 receive at a first frequency, f1, a plurality of spread spread signals transmitted from the plurality of spread spread units. The plurality of spread spread signals are scattered by the plurality of mixers 13, 14, 15. The outputs of the plurality of mixers

13, 14, 15 are a plurality of scattered spread scatter signals. Demodulator 16 demodulates the plurality of scattered spread signals to generate a plurality of demodulated signals. The combiner 17A combines the plurality of demodulated signals. The combined plurality of demodulated signals and a local signal from the base station can be combined by the second combiner 17B to generate a combined signal. The term combined signal is as

522 690 it is used here an analog signal comprising the voice of the base station and the combined demodulated signals from combiners 17A, 17B.

The combined signal is converted to a base data signal by analog-to-digital converter 18. The term base-data signal, as used herein, is the digital signal coming from the analog-to-digital converter 18, and includes the converted analog signals and the data signal at the base station.

The product device 19 spreads the base data signal from analog-to-digital converter 18, with a base chipping sequence. The spread spectrum processed base data signal is transmitted as a base spread spread signal by transmitter 20 at the second frequency f2. Antenna 11 and antenna 21 may be a single antenna serving both the receiver and the transmitter.

The remote subassembly is shown in Figure 2 and comprises a receiver portion, a transmitter portion, a receiving means, a spreading means, and a demodulation means. The transmission portion includes a conversion means, a spread spectrum processing means, and a transmission means. The receiving means receives at the second frequency the baseband spread signal. The spreading means spreads the baseband spread signal to a scattered baseband spread signal. The demodulation means demodulates the scattered baseband spread signal to a base analog signal.

The conversion means converts a remote analog signal to a remote data signal. The remote analog signal is typically the voice of the remote station. The base analog signal is typically the plurality of voice signals from the base station. The band spread processing means processes the remote data signal with a remote chipping sequence. The transmitting means transmits, at the first frequency, the spread spectrum processed data data signal as one of the plurality of spread spread signals received at the base sub-unit.

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As shown in Fig. 2, the receiving means comprises an antenna 31 and RF / IF amplifier and filter circuits 32.

The spreading means and demodulating means are formed as mixer 33 and demodulator 34. respectively. RF / IF amplifiers 5 and filter circuits 32 are connected between antenna 31 and mixer 33. Demodulator 34 is coupled to mixer 33.

The baseband spread signal at antenna 31 is amplified and filtered by RF / IF. The baseband spread signal of 10 is propagated with the base chopping sequence by means of mixer 33 to generate the scattered baseband spread signal. Demodulator 34 demodulates the scattered baseband spread signal to a base analog signal. The output of demodulator 34 is the plurality of voice signals from the base station.

The transmitter section of the remote subassembly may have the converter means configured as analog-to-digital converter 35, the spread-spectrum processing means as product device 36, and the transmission means as transmitter 37 coupled to antenna 38. Product device 36 is connected between the analog-to-digital converter 35 and the transmitter

37.

The analog-to-digital converter 35 converts the voice of the remote signal, which here is designated as the remote analog signal, into a remote data signal. The remote data signal is spread spread using the device 36 using the remote hacking sequence. The output of product device 36 is the spread-spectrum remote data signal. The transmitter

37 transmits the spread spectrum processed remote data signal using antenna 38, as one of the plurality of spread spread signals. Antenna 31 and antenna 38 can be combined as a single antenna that performs both functions.

The command subunit is shown in Figure 3. The command subunit comprises an initiator, a transmit, and a receive. The initiator initiates a command signal after the local user

522 690 activation of the spreading unit. The command signal activates the base subunit of that spreading unit. The transmitting means transmits the command signal to the plurality of spreading units. The receiving means receives the command signal when it is transmitted from another spreading unit. The actuator activates the remote subunit after receiving the command signal.

The initiator is shown in Fig. 3 as a push button switch 43. The transmitter is shown as a transmitter portion by the transmitter / receiver 42. The transmitter transmits at frequency f3. The receiving means is shown as the receiver portion of the transmitter / receiver 42. The receiver receives at frequency f3. Transmitter / receiver 42 is connected to antenna 41 to transmit and receive signals. The actuator includes the necessary circuits to disconnect the base subassembly and activate the remote subassembly of a specific spread spectrum unit. The actuator is shown as the control circuits 44. The present invention can also be used for data instead of voice signals.

In use, a specific spread spectrum unit may operate with its remote subunit activated. Thus, the remote subunit of the specific spread-spectrum unit receives at the second frequency the baseband spread signal, and spreads the baseband spread signal to a strip the baseband spread signal. The scattered baseband spread signal is demodulated. Thus, the specific spread spectrum unit receives all the base signals via its remote subunit. As it transmits to the plurality of spread-spectrum units, the specific spread-spectrum unit converts the voice signal, designed as the remote analog signal, to the remote data signal. The remote data signal is spread spread and processed at the first frequency as one of the plurality of spread spread signals.

After initiating the command signal by the user of the specific spreading unit, by pressing pushbutton 43, the specific spreading unit switches from operating with the remote rounding unit to

522 690 to operate with the base subunit. At the same time, the command signal is transmitted to the other spreading units among the plurality of spreading units. After receiving the command signal, each of the spreading units activates its remote subunit and then operates in a remote subunit mode. The specific spreading unit has then become the base station.

When operating as a base station, the specific spreading unit has its base subunit activated. Accordingly, the plurality of spreading signals transmitted from the plurality of spreading units at each unit are received by the RF / IF amplifier and filter circuits 21 via antenna

11th The plurality of spread spread signals are propagated by the plurality of mixers 13, 14, 15, and demodulated by the demodulator 16 which outputs a demodulated signal. The plurality of demodulated signals from combiner 17A are the voices of the multiple remote stations. The voices from the multiple remote stations are combined with the base station's voice by combiner 17B, and converted by analog-to-digital converter 18 into the base data signal. The base data signal is spread spread using the product device 19 and transmitted by transmitter 20 and via antenna 21 at the second frequency.

It will be appreciated by those skilled in the art that various modifications may be made to the spread spectrum variable base station of the present invention without departing from the scope of the invention, and the present invention is intended to cover modifications and variations of the spread spectrum variable base station, provided they fall within the scope of the appended claims.

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