MXPA00011640A - Apparatus and method for processing signals selected from multiple data streams - Google Patents

Abstract

A multiple data stream processing arrangement includes a receiver/signal processor (14) and a plurality of signal input paths (11, 12) which meet at a junction (36). A junction output from the junction (36) provides a single input to the receiver/signal processor (14). A switching arrangement (16) is associated with the plurality of signal input paths (11, 12). The switching arrangement (16) includes a switch (31, 32) connected in each signal input path (11, 12). Each switch (31, 32) responds to an enable signal to allow a data stream applied to the respective input path (11, 12) to pass on to the junction (36) and to the receiver/signal processor (14). According to the invention only one signal input path (11, 12) and respective switch (31, 32) is enabled at any given time.

Description

APPARATUS AND METHOD FOR PROCESSING SELECTED SIGNALS FROM MULTIPLE DATA CURRENTS FIELD OF THE INVENTION This invention relates to the transmission of digital data and more particularly to an apparatus and method for selecting between multiple streams of data, to produce a single data output.

BACKGROUND OF THE INVENTION Various types of information can be converted to a digital format and the digital data can then be transmitted to a user's location, such as a radio frequency signal containing a stream of digital data. A single-user location may be able to receive these digital radio frequency transmissions from multiple sources. For example, a user may receive signals directed from one or more terrestrial transmitters. Also, the same user may be able to receive digital radiofrequency signals from one or more satellites. Regardless of the source of the radiofrequency signals that contain the digital data stream, each data stream must be processed at the user's location to provide useful information. Direct transmission satellite television broadcast (DBS) is an example of digital radio frequency transmission. In the DBS transmission the digital signals that are in a number of different carrier frequencies, are transmitted from a satellite and these multiple carrier frequencies together contain a data stream. The frequency spectrum now assigned to the DBS transmissions comprises the spectrum of 12.2 5 to 12.7 GHz. Each carrier frequency conducts data for several different discrete outputs, which in the DBS example, comprise television channels. In order to use the data stream of the DBS, all the data stream is picked up by an appropriate antenna and the frequencies are converted down to an intermediate frequency below the radio frequency level. A receiver at the user's location demodulates the desired carrier frequency and decodes the demodulated signals to produce a desired output containing a channel input for a television set.

SUMMARY OF THE INVENTION An object of the invention is to provide an apparatus and method for selecting between multiple streams of data transmitted on one or more common frequencies and processing the selected data stream. To achieve this object, an apparatus according to the invention includes a plurality of signal input paths, to a single receiver / signal processor. A switching facility, associated with the signal input paths, allows only one of the routes at a particular time, to communicate a data stream to the receiver / signal processor. Each input path of 30 signals can receive a separate data stream that feai1 »a« aa8.a »jAgfai .-« j. ^ _ t "M & amp; amp; al &ktiitA ~~ _ > -. *. - £ > - ~ - - ° ~ r * - * - * • • • • • - ** S - - ^., _ ____ include signals that are on one or more frequencies that may or may not be common to the frequencies for signals received in another of the entry routes. By allowing only one input route at a time, the switching facility prevents common frequency signals from interfering with each other. In addition, all signals from each source can be processed by the only receiver / signal processor, thus avoiding duplicating the equipment for signal processing at the user's location. As used in this description, the term "data stream" means transmissions of digital data in one or more frequencies, coming from a single source. The frequency or frequencies can be any frequency, including radio frequencies and lower frequencies. For example, a data stream may contain signals transmitted to radio frequencies from a satellite and may also comprise the same signals after down-conversion to intermediate frequencies. As well, as used herein, "data" shall mean any digital data and shall not be limited to data that produces some type of particular output. For example "data" may comprise the digital signals required to produce a television input for a standard television set. As another example, "data" may comprise digital signals that represent communications over interconnected networks (Internet). Still as another example, "data" may comprise digital voice or telephone information. The switching installation includes a suitable switching device, connected in each path . , "^ .._ Od -t» »^ - - *» «« »-« n ^ ti ^ í ~ • - - »^ - ~ -1 ~ - - - - w ^ aai ^ ** - * entry. Each switching device is enabled to pass the data stream only in response to a enable signal supplied to the respective switching device. In the absence of a enabling signal, the respective switching device serves to block the data stream that is in the particular input path. The plurality of input paths is at a junction point that has a single output that is connected to the input of the receiver / signal processor. The receiver / signal processor receives signals from the only enabled input path and processes the signals in a manner well known in the art, to produce a desired data output. The apparatus according to the invention has associated with it a separate radiofrequency receiving facility for each signal input path. Each radio frequency receiving facility includes a suitable antenna to receive signals from a single transmission source. Each radio frequency receiver installation also includes a suitable down converter, to convert the radio frequency signals into intermediate frequency signals. Each separate data stream, of the intermediate frequency signals, is applied to a different signal input path in the processing apparatus according to the invention. In a preferred form of the invention, the processing apparatus includes a controller for controlling the switching facility and the different components of the receiver / signal processor. The controller responds to a selected input entered by the user, which is associated with certain data that is in one of the input data streams that can be processed to produce a desired data output. In response to a selected input, the controller retrieves from a memory device, signal input information, to control the switching facility and the signal processing information, to control the signal receiver / processor. The controller uses the signal input information to enable the signal input path that drives the data stream containing the data for the selected output. The information for signal processing causes the receiver / signal processor to tune to the correct carrier frequency which conducts the desired data, demodulates the transmitted signals and finally decodes the demodulated signals, to produce the desired data output. These and other objects, advantages and characteristics of the invention will be apparent from the following description of the preferred embodiments, considered in conjunction with the attached drawing.

BRIEF DESCRIPTION OF THE DRAWING Figure 1 is a schematic representation of an apparatus for the processing of multiple data streams, incorporating the principles of the invention.

DESCRIPTION OF THE PREFERRED MODALITIES Referring to Figure 1, an apparatus 10 for processing multiple data streams, according to the invention, receives a data stream in a first input path 11 and a separate and distinct data stream, in a second path input 12. The apparatus 10 includes a signal receiver / processor 14 to receive one of the two data streams and process the data stream to produce a desired channel output of the signals received. A switching facility 16 allows only one stream of data to arrive at the receiver / signal processor 14 at a time. The apparatus 10 is located at a user location which can be any location that can receive stream of data from multiple sources of data. signs Data streams contain data digita_.es transmitted from a source of suitable radio-frequency signals. Each data stream includes at least one carrier frequency and preferably several carrier frequencies. Each carrier frequency carries data that can be processed to produce at least one channel output. In most cases a single carrier frequency will conduct data that can be processed to produce several different channel outputs. The term "channel output" is used in this description, for convenience, to describe related data that can be used to produce a desired output. For example, the output of the channel may be a suitable signal for use by a television. However, the invention is not limited to the use with data streams containing signals to produce a television input. In the illustrated example of the invention, signals from a radiofrequency transmitter (not shown) are received at a first antenna 21. The signals containing the transmitted data stream can be in any radio frequency range. For example, the radiofrequency transmissions received by the first antenna may be in the range of 12.2 to 12.7 GHz, the frequency band commonly assigned to DBS television transmissions. The radiofrequency signals received in the first antenna 21 are directed to a block converter, low noise or LNB 23 where the signals are converted down to an intermediate frequency. The data stream in the intermediate frequency band is directed towards the first input path 11 of the processing apparatus 10. The intermediate frequency band may be, for example, from about 950 to 1450 MHz. It is possible that the intermediate frequency could be between another frequency range, however, this range of 950 to 1450 MHZ is useful for purposes of illustration, because it corresponds to a range of intermediate frequencies produced from DBS signals transmitted to values between 12.2 and 12.7 GHz. The signals from a second radio frequency source (not shown) are received on a second antenna 22 and converted downwards by a second low noise block converter or LNB 24. The LNB 24 converts the radio frequency signals to signals of intermediate frequencies and sends the intermediate frequency data stream to the second input path 12 cel processor apparatus 10. The invention is not limited to signals received from a particular type of signal source. For example, one source may be a satellite, while the other source of radio frequency signals may be a terrestrial transmitter.

Alternatively, both sources of radiofrequency signals may be satellites, or both may be terrestrial transmitters. In any case, the radiofrequency signals received by the first antenna 21 and the second antenna 22 5 may include signals on the same carrier frequencies. Although in certain cases the carrier frequencies received by the two radiofrequency receiving antennas 21 and 22 may be identical, in other applications of the invention the two different sets of signals may include only a few of the same or none of the same carrier frequencies carrier frequencies, and each set may include other carrier frequencies that are not included in the other set. Where the radiofrequency transmissions received on the antennas 21 and 22 share at least one common frequency, all the signals can not be combined in a single propagation path, without interference being present. For example, the first antenna 21 can receive signals at a transmission frequency of 12.2 GHz. The second antenna 22 can receive signals transmitted at the same frequency of 12.2 GHz, but conduct totally different data. In this case, if the signals of the two antennas 21 and 22 were combined in a common signal path, the signals of common frequencies would interfere with each other. The two signal input paths 11 and 12 pass through the switching facility 16. The switching facility 16 includes a first on / off amplifier or switch 31 connected to the first input port 11, and a second on / off amplifier or switch 32 connected in the second input path 12. The first 0 on / off amplifier 31 is connected to lA »Aiu-i» - * SÉÜ ~ < h_, «« »- -..- ^ .- i-, ^ .-;. ^^ ~ J ________ i_____ receive a enable signal, through a first enable line 33, while the second on / off amplifier 32 is connected to receive an enable signal applied on a second enable line 5 34. The output of the first on / off amplifier 31 and the output of the second on / off amplifier 32 are applied as inputs to a junction amplifier 36. The junction amplifier 36 produces a single junction on the output line 37. The elements 31 and 32 may comprise any suitable on / off amplifier, or active switch, while the link amplifier 36 may comprise any suitable summing amplifier. The on / off amplifier 31 operates to pass the intermediate frequency or data stream signals, received in the input path 11, only when an enabling signal is applied to the amplifier, through the input enable line 33. The on / off amplifier 32 operates in a similar manner to pass the intermediate frequency 0 data stream received in the input path 12 only when an enabling signal is applied to the amplifier, through the enabling line of the amplifier. input 34. When a enable signal is not applied to the particular on / off amplifier, 31 or 32, the particular amplifier does not pass the respective data stream to the link amplifier 36. However, when any of the amplifiers on / off 31 or 32 receives a enable signal through its respective enable line 33 or 34, the dat current If it is in the associated input path, it is passed to the union amplifier 36 paia enter it to the receiver / signal processor 14 through line 37. The junction amplifier 36 ensures that the signals are at the correct impedance, to enter them to the receiver / signal processor 14. As will be discussed in detail later, only one of the on / off amplifiers 31 or 32 is enabled in a certain time. In this way, only one of the received data streams is applied as an input to the receiver / signal processor 14 in a certain time. The signal receiver / processor 14 receives the single data stream, from the junction amplifier 36 and produces a desired channel output, similar to a ceiling unit, of a television set, which picks up a direct transmission satellite, such as a receiver unit DSS of RCA or a receiving unit with DVB format The receiver / signal processor 14 includes a tuner at full load and a down converter 40, a demodulator 41, a decoder 42 for error correction towards the end (FEC), and a format demultiplexer / decoder 45. Each of these elements is connected to and controlled by a controller 43, which, in the preferred form of the invention, comprises a suitable processor. When a user selects a particular channel or data component, through a suitable input, executed by the user, such as the illustrated remote control 44 and the remote control signal receiver 46, the controller 43 sends a enabling signal to enable the on / off amplifier 31 or 32 associated with the input path that conducts the desired data signals, thereby selecting the appropriate data stream. The selected data stream is input to the receiver / processor 14 and the controller 43 controls the tuner 40 to tune to the particular carrier frequency containing the desired data. The tuner 40 then passes this selected carrier frequency to the demodulator 41 which demodulates the selected carrier frequency signal, to produce signals containing all the data conducted on that particular carrier frequency. This data, which can commonly include data for several different channel outputs, is passed to the FEC decoder 42 which operates under the control of the controller 43 to correct errors in the digital data that may have occurred in the transmission. The format demultiplexer / decoder 45 then functions under the control of the controller 43 to decode the data and separate the desired data signals from the r data to produce the desired channel output. The desired channel output is routed through the output line 48 to the equipment (not shown) that can use the channel output, such as for example a television or computer apparatus. A memory device 47 associated with the controller 43 stores the information required to control the different components of the receiver / signal processor 14 and also information for the switching facility 16. The stored information includes a channel identifier, unique for a channel or data component, particular, included in one of the data streams received by the input routes 11 or 12. For each channel identifier the memory device 47 stores information of the signal path that identifies which on / off amplifier 31 or 32 enable, to allow the passage of the desired data to the signal receiver / processor 14. For each signal identifier, the memory device 47 also stores information for the signal processing, which contains all the control information required by the tuner 40, the demodulator 41, the FEC 42 decoder, and the desmultiplexer / descodi 45 format filter, in order to produce the desired channel output. This signal processing information and the manner in which the tuner 40, the demodulator 41, the FEC decoder 42 and the format demultiplexer / decoder 45 operate, is well known in the art and will not be discussed in the present with details. It will be noted that the apparatus 10 illustrated in Figure 1 is presented solely for convenience in the description of the invention. Numerous modifications can be made to the illustrated apparatus 10, within the scope of the invention and the following claims. For example, although Figure 2 shows two entry routes, any number of entry routes can be included in an apparatus that incorporates the principles of the invention. In addition, the invention is not limited to any particular radiofrequency bands or to any particular intermediate frequency bands. Another important aspect of the invention is that the signals in the two different input routes 11 and 12 can drive data in completely different formats, such as for example the DSS, DVB, or MPEG2 formats. Since the memory device 47 stores the particular information for signal processing, to allow the format demultiplexer / decoder 45 to decode the data, there is no limitation as to the particular data format that can be processed by the apparatus 10. Another variation of the form of the invention shown in Figure 1 relates to the switching facility 16. Although the switching facility is presented as integrated with the receiver / signal processor 14, the switches can comprise any device suitable for selectively blocking the respective damage stream and can be located anywhere, in the paths from the respective receiving antennas 21 and 22 to the amplifier of junction 36. These variations in the switch positions should be considered equivalent to the switching facility illustrated in figure 1. Of course, if the switching arrangement is not controlled by the controller 43, some other arrangement can be included to enable the switch wanted. For example, a single manual switch can be used to control the particular switching device and allow the desired data stream to pass to the signal receiver / processor 14. A user selects a particular channel output, which may include a television channel or to another type of data, by providing a selected input to the controller 43 through the user input device 44. The controller 43 responds to the selected input, accessing the memory device 47 to recover the required operational information. The controller 43 locates the channel identifier corresponding to the desired channel output, identified by the selected input and retrieves all the information required to allow the apparatus 10 to process the incoming data in order to produce the output of the channel.

»« «J ^ desired channel. This information includes signal input information which allows the controller 43 to enable the appropriate on / off amplifier, 31 or 32, and allow only the desired data stream to pass, to the signal receiver / processor, 14. The information recovered from the memory device M i * also includes signal processing information for controlling the operation of the tuner 40, the demodulator 41, the FEC decoder 42, and the format demultiplexer / decoder 45, to process the selected data stream and produce the desired channel output, on the output line 48. Since only one signal input path is enabled, at any given time, the multiple data streams do not interfere with each other, even if they include signals that are to one or more common frequencies. The preferred embodiments described above serve to illustrate the principles of the invention and not to limit the scope thereof. Those skilled in the art can perform various other modalities and modifications to these preferred embodiments, without departing from the scope of the following claims. ^^^ a ^^^^^^^^^^^^ H ^^^^^ g ^^^

Claims (20)

NOVELTY OF THE INVENTION

1. An apparatus for processing multiple streams of information, comprising: (a) A signal processing facility having a first input and a second input associated therewith; (b) a first switch connected to the first input and having a first switch output, the first switch for passing signals from the first input to the first switch output in response to an enable signal applied to an associated enable input with the first switch; (c) a second switch connected to the second input and having a second switch output, the second switch for passing signals from the second input to the second switch output in response to the enable signal applied to an associated enable input with the second switch; (d) a data stream junction connected to the first switch output and the second switch output and having a single junction output connected to the signal processing facility; and (e) a controller for selectively applying the enable signal to the enable input of one of the switches, first and second, in order to enable one of such switches to pass signals from the respective input to the respective switch output for be applied to the signal processing installation through the data stream connection.

2. The apparatus of claim 1, wherein: (a) the first input and the first switch receive a first plurality of channels and the second input and the second switch receive a second plurality of channels different from the first plurality of channels; and (b) the controller includes a processor for receiving a channel selection input that identifies a particular channel to be processed between the first and second plurality of channels and, in response to the channel selection input, for applying the signal Enabling one of said first and second switches, which receives the particular channel, and to control the operation of the signal processing facility to produce a channel output from the signals passing through the switch receiving the signal. enabling signal. The apparatus of claim 2, wherein: (a) the controller further includes a memory device associated with the processor, for each different channel selection input, unique signal processing information for the respective channel associated with the channel selection input and signal input information indicating in which input the channel is received; (b) the processor responds to the channel selection input by retrieving the signal input information associated with the particular channel, and applying the enable signal to the switch associated with the input in which the channel is received. The apparatus of claim 1, wherein the signal processing facility includes: (a) a full load tuner and a down converter; (b) a demodulator; (c) a forward error correction decoder; and (d) a format demultiplexer / decoder. The apparatus of claim 1, wherein the data stream junction comprises: (a) an impedance matching amplifier. The apparatus of claim 1, wherein: (a) the first input is connected to receive signals from a first antenna; and (b) the second input is connected to receive signals from a second antenna. The apparatus of claim 1, wherein: (a) the first input receives signals in a first frequency band having a plurality of carrier frequencies; and (b) the second input receives signals in substantially the first frequency band at substantially the same carrier frequencies as those received by the first input. 8. An apparatus for processing multiple streams of data, the apparatus comprising: (a) a receiver for processing a single stream of data to provide a receiver output; (b) a plurality of output paths, each to carry a data stream to the receiver; (c) a plurality of switches that include a different switch connected in each input path _ -? & *, & > & - > ^ differently, each respective switch to block the data stream in the respective input path in the absence of a enable signal applied to said respective switch; and (d) a controller for selectively applying the enable signal to one of the switches to enable a desired of the data streams to reach the receiver. The apparatus of claim 8, wherein: (a) each data stream comprises a single plurality of channels; and (b) the controller includes a processor for receiving a channel selection input identifying the particular channel to be processed from among the different pluralities of channels and, in response to the channel selection input, for applying the enable signal. to the switch associated with the input path conveying a data stream in which the particular channel is received, and to control the operation of the receiver to produce as output from the receiver a channel output for the particular channel. The apparatus of claim 9, wherein: (a) the controller further includes a memory device for storing a plurality of channel identifiers, each channel identifier associated with a different channel selection input, and for each identifier of channel the memory device further stores unique signal processing information for a particular channel of the channels, and input information indicating in which route the data stream including the particular channel is received; and (b) the processor responds to the channel selection input by retrieving the signal processing information associated with the respective channel, and applying the enable signal to the switch associated with the data stream in which the channel is contained. . The apparatus of claim 8, wherein the signal processing facility includes: (a) a full load tuner and a down converter; (b) a demodulator; and (c) a forward error correction decoder. The apparatus of claim 8, further comprising: (a) an impedance matching amplifier adapted to receive signals from each input path and apply signals from said routes to the receiver at a coupled impedance. The apparatus of claim 8, wherein: (a) each data stream comprises signals from a different antenna. The apparatus of claim 8, wherein: (a) each data stream comprises signals in substantially a first frequency band having a plurality of carrier frequencies. The apparatus of claim 14, wherein: (a) each data stream uses substantially the same carrier frequencies. 16. A method for processing multiple data streams, the method comprises the steps of: (a) directing a plurality of different data streams, each along a different input path to a receiver; (b) selectively blocking each of the data streams, except one stream of data so that only one stream of data is applied to the receiver in a given time; and (c) processing the single data stream applied to the receiver to produce a desired channel output from said data stream. The method of claim 16, wherein each data stream includes a plurality of different channels, each different channel associated with a different channel identifier, and wherein the step of selectively blocking each data stream except one stream of data comprises: (a) receiving a caral selection entry indicating the channel identifier of a desired channel; (b) using the channel identifier of the desired channel to identify the particular data stream that includes the desired channel; and (c) applying a enable signal only to a switch associated with the data stream that includes the desired channel to enable said data stream to be applied to the receiver. (b) the processor responds to the channel selection input by retrieving the signal processing information associated with the respective channel, and applying the enable signal to the switch associated with the current of - aflasasufr, - ^ s4Afe ± á & xs & w data in which the channel is contained. The method of claim 16, further comprising the steps of: (a) using the channel identifier of the desired channel to recover from a memory storage device unique signal processing information for the desired channel and that can be used by the receiver to produce the desired channel output from the data stream that includes the desired channel; and (b) controlling the receiver with the signal processing information to produce the desired channel output. The method of claim 16, wherein: (a) each data stream comprises signals in substantially a first frequency band having a plurality of carrier frequencies. The method of claim 19, wherein: (a) each data stream uses substantially the same carrier frequencies.