METHOD AND APPARATUS FOR AUTOPROGRAMMING A TELEVISION RECEIVER

Abstract: An apparatus for automatically programming information associated with a plurality of air and cable television channels. Upon receiving an autoprogramming signal, the apparatus detects analog and digital television signals from each channel to determine whether the associated air or cable channel is digital or analog. The apparatus stores information associated with the each channel into a memory unit. The results of all channels are displayed as a channel scanning list on an output device or monitor. A method for processing a plurality of air and cable television channels is also provided. The method selects a channel, receives an analog or digital signal associated with the selected channel, determines whether the channel is analog or digital, stores the result and repeats the steps until all channels have been selected. Additionally, a computer readable medium that stores a software program is provided. This program, when executed by a computer, causes the computer to perform the method embodied in the invention.

Description: METHOD AND APPARATUS FOR AUTOPROGAMMING A TELEVISION RECEIVER FIELD OF THE INVENTION The invention generally relates to television systems. More particularly, the invention relates to a method and apparatus for autoprogramming analog and digital television signal information associated with broadcast and cable channels. DESCRIPTION OF THE PRIOR ART Television receivers use channel autoprogramming algorithms and systems for automatically detecting active television channels and indicating these channels in a scanning list. The channels may comprise broadcast or air channels for transmitting radio frequency (RF) signals to the receiver via an antenna. Alternatively, the channels may comprise cable channels for transmitting RF signals to the receiver via a cable network. The current autoprogramming algorithms and systems are limited to processing analog television channels. One such autoprogramming algorithm and system is described in U.S. Patent No. 4,776,038, issued to Testin et al. on October 4, 1 988. Recent advances and increased use of digital television systems have created a need for autoprogramming digital television channels. However, the analog television receivers cannot autoprogram the signals associated with the digital television channels. As such, separate systems are typically required for detecting and indicating the respective analog and digital television channels. Therefore, there is a need for a method and apparatus for extending the autoprogramming algorithms and systems to incorporate digital television channels. SUMMARY OF THE INVENTION The invention overcomes the disadvantages of the prior art by providing a method and apparatus for extending the autoprogramming algorithms and systems to incorporate digital television channels. Specifically, the apparatus comprises a tuner, a digital signal converter, an analog signal converter, a video processor, a microprocessor and a memory unit. The tuner converts a radio frequency (RF) signal into an intermediate frequency (IF) signal. The analog signal converter demodulates the IF signal from the tuner into a baseband analog signal and generates tuning and video synchronization signals. The digital signal converter downconverts the IF signal into a near baseband signal, demodulates the near baseband signal into a baseband digital signal, and generates synchronization and error correction signals. The video processor further processes video and audio components of the respective baseband analog and digital signals for display on an output device. The memory unit stores the autoprogramming algorithm and information associated with the analog and digital television channels. The microprocessor executes the autoprogramming algorithm or program that is stored in the memory unit. The microprocessor controls the tuner, receives signals from the analog and digital signal converters, determines the type of channel based on the received signals, stores the result in the memory unit and repeats the procedure for each available channel until all channels are processed. A method for processing a plurality of television channels is also provided. Specifically, the method comprises the steps of selecting a channel from a plurality of channels, receiving a signal associated with the selected channel, and determining whether the selected channel is digital or analog, storing information associated with the selected channel into a memory unit. These steps are repeated for each of the plurality of channels. Additionally, a computer readable medium that stores a software program is provided. This program, when executed by a computer, causes the computer to perform the method embodied in the invention. BRIEF DESCRIPTION OF THE DRAWINGS The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which: FIG. 1 depicts a block diagram of a television receiver capable of receiving analog and digital signals; FIG. 2 depicts a flow chart of a method for scanning various channels; FIG. 3 depicts a flow chart of a method for detecting whether a channel is analog, digital or neither; and FIG. 4 depicts a flow chart of a method for detecting a whether a channel is digital. To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. DETAILED DESCRIPTION FIG. 1 depicts a block diagram of a television receiver 1 00 capable of receiving analog and digital television signals. The receiver 1 00 comprises a tuner 1 02, a digital demodulator 1 04, a forward error correction (FEC) module 106, a digital signal processor 1 08, an analog demodulator 1 1 0, an analog signal processor 1 1 2, a microprocessor 1 1 4, a memory unit 1 1 6 and a video processor 1 1 8. Additionally, the receiver 1 00 interfaces with a signal interface 1 20, an input device 1 22 and an output device 1 24. The tuner 1 02 receives modulated radio frequency (RF) signals via a signal interface 1 20. Different signal interfaces 1 20 are required depending on whether the received RF signals are associated with air channels (also known as broadcast channels) or cable channels. If the tuner 1 02 receives television signals from air channels, then the signal interface 1 20 comprises an antenna. If the tuner 1 02 receives television signals from cable channels, then the signal interface 1 20 comprises a cable network connection. The signal interface 1 20 may receive various signal types from various sources. The RF signals associated with air and cable channels are analog and digital television signals. The analog television signal may comprise a conventional National Television Standard Committee (NTSC) modulated signal within the United States. The digital television signal may comprise a Vestigial Sideband (VSB) modulated signal in compliance with the Advanced Television Systems Committee (ATSC) standard A/53. The tuner 1 02 converts or heterodynes the received RF signal into an intermediate frequency (IF) signal. Once the microprocessor 1 1 4 receives an autoprogramming command from the input device 1 22, the microprocessor 1 1 4 initiates a search of the active channels. For each channel, the microprocessor 1 1 4 sends a voltage signal to the tuner 1 02 that corresponds to the required local oscillator (LO) frequency. After the microprocessor 1 1 4 determines the appropriate LO frequency for a selected channel, the tuner 1 02 converts the RF signal into an IF signal. In the United States, the IF of the video carrier is 45.75 MHz for the analog television signal and 44 MHz for the digital television signal. After the tuner 1 02 converts the received television signal into an IF signal, the television receiver 1 00 processes the digital and analog IF television signals. Specifically, the television receiver comprises a digital signal converter 1 26 to process the IF digital television signal and an analog signal converter 1 28 to process the IF analog television signal. The digital signal converter 1 26 comprises the digital demodulator 104, forward error correction module 1 06 and the digital signal processor 1 08. The analog signal converter comprises an analog demodulator 1 1 0 and the analog signal processor 1 1 2. The video processor 1 1 8 further processes the video and audio components of the respective analog and digital television signals into a suitable format for display on the output device 1 24. The digital demodulator 1 04 downconverts the IF digital television signal into a near baseband (NBB) signal, performs carrier lock on the NBB signal to convert the NBB signal to a baseband digital symbol stream, and performs symbol timing on this symbol stream. To perform these functions, the digital demodulator 104 includes a frequency downconverting stage, a carrier recovery loop and a symbol timing recovery loop. The frequency downcoverting stage receives the IF signal, centered at 44 MHz, from the tuner 1 02 and downconverts the IF signal frequency to a NBB frequency, e.g., 5.38 MHz (or half the symbol rate of the digital data stream). The carrier recovery loop generates a local oscillator (LO) signal that is matched or phase-locked to the carrier in the NBB signal. Once phase lock occurs, this loop generates a Carrier Lock signal to the microprocessor 1 1 4. The carrier recovery loop then mixes the LO signal with the NBB signal for removing the carrier in the NBB signal and converting the NBB signal to a baseband data stream. After sending the Carrier Lock signal, the symbol timing recovery loop matches or phase-locks the baseband data stream for recovering a data symbol stream from the baseband data stream. The data stream comprises a sequence of data fields. Each data field includes one field synchronization (sync) segment and 31 2 data segments. Each data segment includes 4 segment sync symbols and 828 symbols for payload and error check. These 4 segment sync symbols represents a segment sync word. If the digital television signal is an 8-VSB signal, then the payload symbols include a 1 88-byte MPEG-2 data packet and the error check symbols include 20 parity bytes. As each sync segment includes one segment sync word, the segment sync words are periodic within the data stream, illustratively, at 1 0.76 Msymbols/sec. In the case of an 8-VSB digital television signal, the segment sync word includes a reference pattern of 1 , - 1 , - 1 , 1 . Once the digital demodulator correlates the segment sync word to a predetermined level of confidence, the digital demodulator 1 04 sends a Segment Lock signal to the microprocessor 1 1 4. After the digital demodulator 1 04 achieves segment lock, the forward error correction (FEC) module 1 06 detects and corrects errors in the demodulated digital signal. To compensate the effects of changing conditions and disturbances in the signal transmission channel, the FEC module 1 06 comprises an adaptive equalizer for removing the channel distortions or performing channel equalization. However, the adaptive equalizer may introduce a variable delay to the data stream. As such, the data stream from the equalizer may no longer be aligned with the segment synchronization signals. The FEC module 1 06 must realign the data stream to the segment sync signals for enabling forward error correction of the data streams. When this occurs, the FEC module 1 06 provides a FEC Lock signal to the microprocessor 1 1 4. Additionally, the FEC module 1 06 comprises an error correction module such as a Reed Solomon decoder. The Reed Solomon decoder uses the 20 parity bytes in each segment for correcting the 1 87 data bytes in each data packet. The Reed Solomon decoder may correct up to 1 0 erroneous bytes per packet. As such, the packet contains uncorrectable errors if the packet contains more than 1 0 erroneous bytes. The number of uncorrectable packet errors per second is the Reed Solomon Error Rate. If the error rate is sufficiently low, then the FEC module 1 06 sends a Reed Solomon Error Rate signal to the microprocessor 1 14. However, if this error rate is too high, then the digital signal processor 1 08 may not properly decode the associated video and audio information in the data stream. The digital signal processor 1 08 separates the baseband digital signal or data stream into video and audio component signals. The video processor 1 1 8 further processes the component signals into a suitable format for display on the output device 1 24. The output device 1 24 is television monitor or some other display device. The analog demodulator 1 1 0 demodulates the analog IF modulated signal into a baseband signal comprising video and audio components. Additionally, the analog demodulator 1 10 comprises an automatic fine tuning (AFT) circuit for determining whether the video component of the IF signal deviates from the nominal IF frequency of 45.75 MHz. If the frequency of the video component is above 45.75 MHz, then the AFT circuit decides that the video component frequency is too high and provides a "00" value to the microprocessor 1 1 4. If the frequency of the video component is below 45.75 MHz, the AFT circuit decides that the video component frequency value is too low and provides a " 1 1 " value to the microprocessor 1 1 4. Other possible values of the AFT circuit are also contemplated within the scope of the invention. The analog signal processor 1 1 2 separates the baseband analog television signal into video and audio component signals. As with the corresponding video and audio signals of the digital television signal, the video processor 1 1 8 further processes the component analog television audio and video signals for display on the output device 1 24. Additionally, the analog signal processor 1 1 2 derives a composite synchronization ("SYNC") signal from the video signal. Such a composite SYNC signal typically comprises horizontal and vertical video synchronization signals. The composite SYNC signal is coupled to the microprocessor 1 1 4. The microprocessor 1 1 4 coordinates the channel detection and autoprogramming functions associated with the television receiver 1 00. Initially, the microprocessor 1 1 4 receives an autoprogramming command from the input device 1 22 such as a remote control, keyboard or other devices for entering data. For example, the input device 1 22 may direct the microprocessor 1 1 4 to search all of the active air and/or cable channels. As the air and cable channels are used for transmitting analog and digital television signals, the microprocessor 1 1 4 detects the type of television signal for each channel searched. Once the microprocessor 1 1 4 detects the type of television signal transmitted over each air and/or cable channel, the microprocessor 1 1 4 stores or loads the channel information in the memory unit 1 1 6. The microprocessor 1 1 4 indicates whether a given air or cable channel is analog or digital depending on the type of television signal detected. The channel information is retrieved from the memory unit 1 1 6 and shown on the output device 1 24 or display. Additionally, the microprocessor 1 1 4 executes software programs to properly detect whether the channels associated with television signals are analog, or digital. The software programs are stored in the memory unit 1 1 6 such as a read only memory (ROM). Upon executing the software programs, the microprocessor 1 1 4 utilizes signals from the digital demodulator 1 04, the FEC module 1 06, the analog demodulator 1 1 0 and the analog signal processor 1 1 2. These signals include Carrier Lock and Segment Lock signals from the digital demodulator 1 04 , and FEC Lock and Reed Solomon Error Rate signals from the FEC module 1 06. The microprocessor 1 1 4 initially scans the channels as depicted in FIG. 2. For each channel that is receivable, the associated television signal is determined as being either analog or digital as further depicted in FIG. 3. Specifically, as depicted in FIG. 4, if the television signal is not digital, then the AFT signal from the analog demodulator 1 1 0 and the composite SYNC signal from the analog signal processor 1 1 2 are used to determine whether the television signal and corresponding channel is analog. Each channel is marked as either analog or digital depending on the type of television signal. Finally, the channel information is automatically programmed into the memory unit 1 1 6, e.g., a random access memory (RAM) or an electrically erasable programmable read only memory (EEPROM) . The channel information is displayed on the output device 1 24 as a channel scanning list. As the information about the channels is stored in the memory unit 1 1 6 and displayed on the output device 1 24, the television receiver 1 00 does not need to determine whether the user selected channel is analog or digital. As such, once a channel is selected, the time required for tuning that channel is reduced. The present invention may also be implemented as a program product for use with a computer system, e.g., a television system. The program(s) of the program product defines functions that can be contained on a variety of signal/bearing media, which include, but are not limited to, (i) information permanently stored on non-writable storage media, (e.g., read-only memory devices within a computer such as CD-ROM disks readable by a CD-ROM drive); (ii) alterable information stored on writable storage media (e.g., floppy disks within a diskette drive or hard-disk drive); or (iii) information conveyed to a computer by a communications medium, such as through a computer or telephone network, including wireless communications. Such signal-bearing media, when carrying computer-readable instructions that direct the functions of the present invention, represent additional embodiments of the present invention. FIG. 2 depicts a flow chart of a method 200 for detecting a plurality of channels. The microprocessor 1 1 4 executes a software program (that embodies this method 200) to scan or select channels. After detecting all of the selected channels, the microprocessor 1 1 4 stores or loads the information associated with the channels into the memory unit 1 1 6. The method 200 initially selects an initial channel at step 202. The method 200 proceeds to at step 203, for determining whether the present channel is a digital channel. Step 203 is embodied in a method 400 as further described in FIG. 4 below. If the channel is digital, the method 200 proceeds to step 204, where the present channel is marked as a digital channel. If the channel is not digital, then the method 200 proceeds to step 206 for determining whether the present channel is an analog channel. If the selected channel is analog, then the method 200 proceeds to step 208, where the present channel is marked as an analog channel. Otherwise, the method 200 proceeds to step 21 0, where the present channel is marked as neither a digital channel nor an analog channel. The combination of steps 203 and 206 is embodied in a method 300 as further described in FIG. 3 below. As such, method 300 determines whether the present channel is digital or analog. After the method 200 marks the channel in respective steps 204, 208 and 21 0, the method 200 proceeds to determine whether all the channels have been selected or searched at step 31 2. If all the channels have been selected, the method 200 proceeds to step 21 4 and stops. If there are additional channels to select, the method 200 proceeds to select the next available channel at step 21 6 and repeats itself (method 200) until all channels have been selected. As previously mentioned, the combination of steps 203 and 206 is embodied within a method 300. FIG. 3 depicts a flow chart of a method 300 for detecting whether the channel is analog, digital, or neither analog nor digital. The method 300 processes analog and digital signals associated with the selected air and cable channels. The method 300 is implemented each time a new channel is selected or scanned. The channel detection method 300 starts at step 302. The method 300 proceeds to step 304, where the LO frequency is selected such that the tuner 1 02 converts the incoming RF signal to an intermediate frequency (IF) equivalent to a nominal frequency value, i.e., 44 MHz for a digital television signal. At step 306, the method 300 presumes that the television receiver 100 receives a digital television signal. The method 300 proceeds to step 307 to determine whether the selected or scanned channel is digital. Step 307 is embodied in the method 400 of FIG. 4. If the channel is digital, then the method 300 proceeds to step 204, where the channel is detected and marked as a digital channel. If the channel is not digital, then the method 300 proceeds to step 308, where the method 300 presumes that the television receiver 1 00 receives an analog television signal. The method 300 proceeds to step 31 0, where the frequency of the LO is set such that the tuner 1 02 converts the incoming RF signal to an IF that is 0.1 875 MHz above the nominal IF frequency. The nominal IF is 45.75 MHz for the video carrier portion of the analog television signal in the United States. The 0.1 875 MHz deviation represents three 62.5 kHz steps, where each 62.5 kHz step or increment represents the resolution of the phase lock loop (PLL) integrated circuit (IC) in the tuner 1 02. This 0.1 875 MHz deviation represents a far enough deviation from the nominal IF frequency, such that the AFT circuit may determine whether the converted IF frequency is too high or too low. At step 31 2, the method 300 determines whether the automatic fine tuning (AFT) value is 00. If the AFT value equals 00, then the method 300 proceeds to step 31 4. If the AFT value is not 00, then the method 300 proceeds to step 31 6. At step 31 4, the frequency of the LO is set such that the tuner 1 02 converts the incoming RF signal to an IF that is 0.1 875 MHz below the nominal frequency. The method 300 proceeds to step 31 8 for determining whether the AFT value equals 1 1 . If the AFT equals 1 1 , then the method 300 proceeds to step 320. In this case, the video component of the IF analog television signal is properly centered about the nominal IF of 45.75 MHz. If the AFT does not equal 1 1 , then the method 300 proceeds to step 31 6. At step 320, the method 300 determines whether the microprocessor 1 1 4 detects the SYNC (synchronization) signal from the analog processor 1 1 2. If the microprocessor 1 1 4 detects the SYNC signal, then the method 300 proceeds to step 322. If the microprocessor 1 1 4 fails to detect the SYNC signal, then the method 300 proceeds to step 31 6. At step 322, method 300 determines that the received television signal is analog. The method 300 proceeds to step 208, where the microprocessor 1 1 4 marks the detected channel as an analog channel and stores the result in the memory unit 1 1 6. At step 31 6, the method 300 determines whether the detected channel is a cable channel or an air (broadcast) channel. If the detected channel is an air channel, then the method 300 proceeds to step 21 0, where the microprocessor 1 1 4 marks the channel as neither an active analog or digital channel. This result is stored in the memory unit 1 1 6. If the detected channel is a cable channel, the method 300 proceeds to step 324. At step 324, the method 300 presumes that the television receiver 1 00 receives a digital television signal. The signals associated with cable channels may have a harmonically related carrier (HRC) or an incrementally related carrier (IRC) . The method 300 proceeds step 326, where the frequency of the LO is set such that the tuner 1 02 converts the incoming RF signal to an IF associated with the HRC frequency. The method 300 then proceeds to step 327 for determining whether the cable channel is digital. As with step 307, step 327 is embodied in method 400 of FIG. 4. If the cable channel is digital, then the method 300 proceeds to step 204, where the cable channel is detected and marked as a digital channel. If the cable channel is not digital, then the method 300 proceeds to step 328, where the method 300 presumes that the television receiver 1 00 receives an analog television signal associated with cable channels. At step 330, the frequency of the LO is set such that the tuner 1 02 converts the incoming RF signal to an IF that is 0.1 875 MHz above the HRC frequency. The method 300 proceeds to step 332, where the microprocessor 1 1 4 determines whether the automatic fine tuning (AFT) value equals 00. The AFT value is coupled to the microprocessor through the analog demodulator 1 1 0. If the AFT value equals 00, then the method 300 proceeds to step 334. If the AFT value is not 00, then the method 300 proceeds to step 336. At step 334, the frequency of the LO is set such that the tuner 1 02 converts the incoming RF signal to an IF that is 0.1 875 MHz below the HRC frequency. The method 300 proceeds to step 338, where the microprocessor 1 1 4 determines whether the AFT signal equals 1 1 . If the AFT signal equals 1 1 , then the method proceeds to step 340, where the method 300 determines whether the microprocessor 1 14 detects the SYNC (synchronization) signal from the analog processor 1 1 2. If the microprocessor 1 1 4 detects the SYNC signal, then the method 300 proceeds to step 322 and then to step 208 for detecting the cable channel as analog. If the microprocessor 1 1 4 fails to detect the SYNC signal, then the method 300 proceeds to step 21 0, where the cable channel is detected as neither an analog or digital channel. At step 336, the microprocessor 1 1 4 determines whether the selected cable channel is either channel 5 or 6. As the HRC and IRC frequencies are the same for all cable channels except cable channels 5 and 6, the method 300 determines whether a cable signal is located at IRC frequency for cable channels 5 or 6. If the selected cable channel is channel 5 or 6, then the method 300 proceeds to step 342. Otherwise, there is no need to locate any additional signals and the method 300 proceeds to step 21 0, where the cable channel is detected as neither an active analog nor digital channel. At step 342, the method 300 presumes that the television receiver 1 00 receives a digital television signal. The method 300 proceeds step 344, where the frequency of the LO is set such that the tuner 1 02 converts the incoming RF signal to an IF associated with the IRC frequency. The method 300 then proceeds to step 345 for determining whether the cable channel is digital. As with steps 307 and 327, step 345 is embodied in method 400 of FIG. 4. If the cable channel is digital, then the method 300 proceeds to step 204, where the cable channel is detected and marked as a digital channel. If the cable channel is not digital, then the method 300 proceeds to step 346, where the method 300 presumes that the television receiver 1 00 receives an analog television signal associated with cable channels. The method 300 proceeds to step 348, where the local oscillator frequency is set such that the tuner 102 converts the incoming RF signal to an IF that is 0.1 875 MHz above the IRC frequency. At step 350, the microprocessor 1 14 determines whether the automatic fine tuning (AFT) value equals 00. If the AFT value equals 00, then the method 300 proceeds to step 352. If the AFT value is not 00, then the method 300 proceeds to step 328. At step 352, the frequency of the LO is set such that the tuner 1 02 converts the incoming RF signal to an IF that is 0.1 875 MHz below the IRC frequency. The method 300 proceeds to step 354, where the microprocessor 1 1 4 determines whether the AFT signal equals 1 1 . If the AFT signal equals 1 1 , then the method 300 proceeds to step 340, where the method 300 determines whether the microprocessor 1 1 4 detects the SYNC (synchronization) or video synchronization signal from the analog processor 1 1 2. If the microprocessor 1 14 detects the SYNC signal, then the method 300 proceeds to step 322 and then to step 208 for detecting the cable channel an active analog channel. If the microprocessor 1 1 4 fails to detect the SYNC signal, then the method 300 proceeds to step 21 0, where the cable channel is detected as neither an active analog or digital channel. FIG. 4 depicts a flow chart of a method 400 for detecting a digital channel. The method 400 determines whether a channel, associated with a digital signal, is a digital channel. At step 402, the method 400 initializes a failure timer for two seconds. As such, the method 400 must detect the selected digital channel before the timer times out in two seconds. The timer minimizes the delay introduced by the digital channel detection method 400. The method 400 proceeds to step 404, where the LO frequency is selected such that the tuner 1 02 converts the incoming RF signal to an intermediate frequency (IF) equivalent to a nominal frequency value, 44 MHz for a digital television signal. At step 406, the method 400 determines whether the microprocessor 1 1 4 received the Carrier Lock signal from the digital demodulator 1 1 4. If the microprocessor 1 1 4 received the Carrier Lock signal, the method 400 proceeds to step 408. If the microprocessor 1 1 4 fails to receive the Carrier Lock signal, the method 400 proceeds to step 41 0. At step 41 0, the LO frequency is selected such that the tuner 1 02 converts the RF signal to an IF equal to 62.5 kHz above the nominal frequency. The 62.5 kHz increment represents the resolution of the phase lock loop (PLL) integrated circuit (IC) in the tuner 1 02. The method 400 proceeds to step 41 2, where the method 400 determines whether the microprocessor 1 1 4 received the Carrier Lock signal after changing the LO frequency. If the microprocessor 1 14 receives the Carrier Lock signal, then the method 400 proceeds to step 408. Otherwise, the method 400 proceeds to step 41 4, where the microprocessor 1 14 marks the detected channel as not digital (or not an active digital channel). At this point, the method 400 concludes and reenters the method 300. At step 408, the method 400 initializes symbol timing of the digital baseband signal. The method 400 proceeds to step 41 6, where the method 400 determines whether the microprocessor 1 1 4 receives a Segment Lock signal from the digital demodulator 104. If the microprocessor 1 1 4 receives the Segment Lock signal, then the method 400 proceeds to step 41 8. If the microprocessor 1 1 4 fails to receive the Segment Lock signal, the method proceeds to step 41 4. As such, the channel is not an active digital channel if the microprocessor 1 1 4 fails to receive either a Carrier Lock or Segment Lock signal. At step 41 6, the method 400 determines whether the microprocessor 1 1 4 receives the FEC Lock signal from the forward error correction (FEC) module 106. If the microprocessor 1 14 receives the FEC Lock signal, then the method 400 proceeds to step 420. If the microprocessor 1 1 4 fails to receive the FEC Lock signal, the method 400 proceeds to step 422. At step 420, the method 400 determines whether the microprocessor 1 1 4 receives the Reed Solomon Error Rate signal from the FEC module 1 06. If the microprocessor 1 1 4 receives the Reed Solomon Error Rate signal, then the method proceeds to step 424. In this case, the microprocessor 1 1 4 detects the selected channel as digital and stores the result in the memory unit 1 1 6. As such, the channel is detected as an active digital channel if there is a carrier lock, a segment lock, a FEC lock and a sufficiently low Reed Solomon error rate before the timer expires. If the microprocessor 1 1 4 fails to receive the Reed Solomon Error Rate signal, the method 400 proceeds to step 422. At step 422, the method 400 determines whether the timer, illustratively two seconds, is expired. If the timer is expired, then the method 400 proceeds to step 41 4, where the channel is not detected as digital. The method 400 then proceeds back to method 300. If the time is still active, then the method 400 proceeds to step 424. At step 424, the method 400 rechecks whether the microprocessor 1 1 4 receives a Carrier Lock signal. If the Carrier Lock is present, then the method 400 proceeds to step 408, where symbol timing is reinitialized. If the Carrier Lock is not present, then the method 400 proceeds to step 404 for effectively reevaluating the digital signal. The methods described herein are not limited to the values or signals illustratively shown. Although various embodiments which incorporate the teachings of the present invention have been shown and described in detail herein, those skilled in the art can readily devise many other varied embodiments that still incorporate these teachings.

Claims: What is claimed is: 1 . A method for processing a plurality of channels, the method comprising the steps of: selecting a channel from the plurality of channels; receiving a signal associated with the selected channel; determining whether the selected channel is digital; determining whether the selected channel is analog; storing information associated with the selected channel ; and repeating said selecting, receiving, digital channel determining, analog channel determining and storing steps until each of the plurality of channels have been selected. 2. The method of claim 1 wherein the information associated with the selected channel is stored into a memory unit. 3. The method of claim 1 wherein said digital channel determining step further comprises the steps of: determining that the received signal is a digital baseband signal; receiving synchronization and error check signals from the received signal; determining whether the generated synchronization and error check signals are proper for a digital television signal; and marking the selected channel as digital if the synchronization and error check signals are proper. 4. The method of claim 3 wherein the synchronization signals comprise a Carrier Lock signal and a Segment Lock signal. 5. The method of claim 3 wherein the error check signals comprise a Forward Error Correction (FEC) signal and a Reed Solomon Error Rate signal. 6. The method of claim 1 wherein said analog channel determining step further comprises the steps of: determining that the received signal is an analog baseband signal; determining whether a video carrier of the analog baseband signal is automatically fine tuned; determining whether a video synchronization signal is detected; marking the channel as analog if the video carrier is automatically fine tuned and the video synchronization signal is detected. 7. The method of claim 6 wherein said video synchronization is a composite SYNC signal having a vertical synchronization signal and a horizontal synchronization signal. 8. An apparatus for automatically programming information associated with a plurality of channels, the apparatus comprising: a tuner for converting a radio frequency (RF) signal associated with each of the plurality of channels into an intermediate frequency (IF) signal; a digital signal converter, coupled to said tuner, for demodulating the IF signal into a baseband digital signal and generating synchronization and error correction signals from the baseband digital signal; an analog signal converter, coupled to said tuner, for demodulating the IF signal into a baseband analog signal and generating tuning and synchronization signals from the baseband analog signal; a video processor, coupled to said digital and analog signal converters, for processing video and audio components of the baseband digital and analog signals to an output device; a memory unit, for storing autoprogramming software and information associated with each of the plurality of channels; and a microprocessor, coupled to said digital signal converter, said analog signal converter, said tuner and said memory unit, for controlling said tuner, receiving signals from said analog and digital signal converters, executing autoprogramming software, determining the type of channel for each of the plurality of channels and storing information about each of the plurality of channels into said memory unit. 9. The apparatus of claim 8 wherein said digital signal converter comprises: a digital demodulator for demodulating the IF signal into a digital baseband signal and generating synchronization signals; a forward error correction (FEC) module, coupled to said digital demodulator, for generating error correction signals; and a digital signal processor, coupled to said FEC module, for separating the digital baseband signal into video and audio components. 1 0. The apparatus of claim 8 wherein the analog signal converter comprises: an analog demodulator for demodulating the IF signal into an analog baseband signal and generating tuning signals; and an analog signal processor, coupled to said analog demodulator, for generating video synchronization signals and separating the analog baseband signal into video and audio components. 1 1 . The apparatus of claim 8 wherein said microprocessor determines the type of channel by executing autoprogramming software stored in said memory unit. 1 2. The method of claim 8 wherein the synchronization signals comprise a Carrier Lock signal and a Segment Lock signal. 1 3. The method of claim 8 wherein the error correction signals comprise FEC Lock and Reed Solomon Error Rate signals. 1 4. A computer readable medium storing a software program that, when executed by a computer, causes the computer to perform a method comprising: selecting a channel from the plurality of channels; receiving a signal associated with the selected channel; determining whether the selected channel is digital; determining whether the selected channel is analog; storing information associated with the selected channel ; and repeating said selecting, receiving, digital channel determining, analog channel determining and storing steps until each of the plurality of channels have been selected. 1 5. The computer readable medium of claim 1 4 wherein said digital channel determining step further comprises the steps of: determining that the received signal is a digital baseband signal; receiving synchronization and error check signals from the received signal; determining whether the generated synchronization and error check signals are proper for a digital television signal; and marking the selected channel as digital if the synchronization and error check signals are proper. 1 6. The computer readable medium of claim 1 4 wherein said analog channel determining step further comprises the steps of: determining that the received signal is an analog baseband signal; determining whether a video carrier of the analog baseband signal is automatically fine tuned; determining whether a video synchronization signal is detected; marking the channel as analog if the video carrier is automatically fine tuned and the video synchronization signal is detected.

Inventors: BOUILLET AARON REEL, JOHNSON GENE HARLOW, MAYER MATTHEW THOMAS, BOUILLET, AARON, REEL, JOHNSON, GENE, HARLOW, MAYER, MATTHEW, THOMAS
Applicants: BOUILLET AARON REEL, JOHNSON GENE HARLOW, MAYER MATTHEW THOMAS, THOMSON LICENSING SA, BOUILLET, AARON, REEL, JOHNSON, GENE, HARLOW, MAYER, MATTHEW, THOMAS, THOMSON LICENSING S.A.
Application year: 2000
Main classification: H04N5
IPC codes: H04N5