Method and apparatus providing channel management in a multi-frequency network broadcasting system

• US 20040244050A1
• Filed: 05/11/2004
• Published: 12/02/2004
• Est. Priority Date: 05/27/2003
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Dong-won
• Granted Patent: US 7,865,930 B2
• Time in Patent Office: Days
• US Class Current: 725/124
• CPC Class Codes: H03J 1/0075 where the receiving frequencies of the stations are stored in a permanent memory, e.g. ROM
• CPC Class Codes: H04H 20/22 Arrangements for broadcast of identical information via plural broadcast systems
• CPC Class Codes: H04H 20/26 Arrangements for switching distribution systems
• CPC Class Codes: H04N 21/426 Internal components of the client ; Characteristics thereof H04N5/44 takes precedence
• CPC Class Codes: H04N 21/4383 Accessing a communication channel
• CPC Class Codes: H04N 21/6112 involving terrestrial transmission, e.g. DVB-T
• CPC Class Codes: H04N 5/455 Demodulation-circuits

Abstract

A method and apparatus providing channel management in a broadcast receiver. The method includes estimating an intensity and a signal-to-noise ratio (SNR) of broadcast signals received via a plurality of physical channels (PCT channels) in a channel memory mode, determining reception quality of the respective plurality of PCT channels, in consideration of both the estimated intensity and SNR of the broadcast signals, and assigning the plurality of PCT channels to a virtual channel (VCT channel) according to a predetermined rule with respect to a reception quality of the plurality of PCT channels.

Claims

1. A method of channel management in a broadcast receiver, the method comprising:

estimating an intensity and a signal-to-noise ratio (SNR) of broadcast signals received via a plurality of physical channels (PCT channels) in a channel memory mode;

determining reception quality of the respective plurality of PCT channels, in consideration of both the estimated intensity and SNR of the broadcast signals; and

assigning the plurality of PCT channels to a virtual channel (VCT channel) according to a predetermined rule with respect to a reception quality of the plurality of PCT channels.

2. The method of claim 1, wherein the intensity of the broadcast signals is estimated by controlling a gain value of an automatic gain control circuit that processes the received broadcast signals.

3. The method of claim 1, wherein the reception quality of the PCT channels is determined by multiplying the intensity and SNR values by first and second weight values, respectively, and combining the results.

4. The method of claim 1, wherein the predetermined rule with respect to the reception quality of the plurality of PCT channels is arranged to assign one of the plurality of PCT channels that has the best reception quality to the VCT channel for the received broadcast signals.

5. The method of claim 1, wherein the predetermined rule with respect to the reception quality of the plurality of PCT channels is arranged to assign the plurality of PCT channels to the VCT channel in the order of the priority of the reception quality of the PCT channels for the received broadcast signals.

6. A method of managing channels in a broadcast receiver, comprising:

evaluating signal intensities and signal-to-noise ratios of broadcast signals carried on a plurality of physical channels (PCT channels); and

assigning a reception channel, among the plurality of physical channels (PCT channels) evaluated, having the best quality to a virtual channel (VCT channel) in a multi-frequency network (MFN).

7. The method of claim 6, wherein the best quality is determined based on signal intensity and signal-to-noise ratio.

8. The method of claim 6, wherein the assigning of the PCT channels is performed in a priority order to the reception quality of the PCT channels.

9. A broadcast receiver comprising:

a tuner which tunes in and outputs broadcast signals via some physical channels (PCT channels);

an automatic gain control (AGC) amplifier which automatically controls and amplifies a gain of the broadcast signals output by the tuner;

an analog-to-digital converter which converts the broadcast signals in an analog form output by the AGC amplifier to digital signals;

a digital demodulator which demodulates the digital signals according to a predetermined rule so as to recover synchronous signals and then recover transmitted symbols using the synchronous signals;

an intensity estimator which estimates an intensity value of the broadcast signals, the intensity value being inversely proportional to the gain of the broadcast signals amplified by the AGC amplifier;

a signal-to-noise ratio (SNR) operation unit which obtains an SNR value of the digital signals, using the symbols recovered by the digital demodulator; and

a controller which calculates a reception quality of the broadcast signals by combining the intensity and the SNR values multiplied by first and second weights, respectively, and assigns a virtual channel for the same broadcast signals received via the PCT channels according to a predetermined channel management rule.

10. The broadcast receiver of claim 9, wherein the predetermined channel management rule with respect to the reception quality of the plurality of PCT channels is arranged to assign one of the plurality of PCT channels that has the best reception quality to the VCT channel for the received broadcast signals.

11. The broadcast receiver of claim 9, wherein the predetermined channel management rule with respect to the reception quality of the plurality of PCT channels is arranged to assign the plurality of PCT channels to the VCT channel in the order of the priority of the reception quality of the PCT channels for the received broadcast signals.

12. The broadcast receiver of claim 9, wherein the SNR operation unit comprises:

an accumulator which accumulates the symbols recovered by the digital demodulator;

an absolute value generator which obtains an absolute value of the result output by the accumulator;

a first adder which adds absolute values in a predetermined period, output by the absolute value generator;

a first mean value generator which obtains a mean value of the absolute values in the predetermined period, output by the absolute value generator;

a second square value generator which obtains an absolute mean square value by squaring the mean value output by the first mean value generator;

a first square value generator which obtains a square value of the result output by the accumulator;

a second adder which adds square values in the predetermined period, output by the first square value generator;

a second mean value generator which obtains a square mean value by averaging the square values in the predetermined period, output by the second adder; and

a variance and signal-to-noise ration (SNR) calculator which obtains a variance by calculating a difference between the absolute mean square value output by the second square value generator and the square mean value output by the second mean value generator, and obtains an SNR value, which is a ratio of the absolute mean square value to the variance.

13. The broadcast receiver of claim 12, wherein the predetermined period is one frame.

14. The broadcast receiver of claim 9, wherein the signal intensity estimator estimates the intensity value of the broadcast signals by using the gain set by the AGC amplifier.

15. The broadcast receiver of claim 9, wherein the digital demodulator demodulates the digital broadcast signal output by the analog-to-digital converter to restore a synchronous signal and then restore a transmitted symbol using the synchronous symbol.

16. The broadcast receiver of claim 15, wherein the demodulation of the digital broadcast signal is performed by a Vestigial Side Band (VSB) sceme.

17. The broadcast receiver of claim 15, wherein the digital demodulator comprises:

a symbol restoration unit to receive a timing error signal of the present recovered symbols which are base band signal processed using a reproduction sampler, and to interpolate the digital broadcast signals received from the analog-to-digital converter by decreasing the error between the digital broadcast signals to obtain digital broadcast signals in synchronization with the symbols;

a band pass matched filter (BFP) to filter the digital broadcast signals in synchronization with the symbols output by the symbol restoration unit;

a phase separator to divide an I signal and a Q signal from the signal filtered by the BFP;

a complex multiplier to receive carrier waves that are restored at a feed back point and to multiply the I and Q signals output by the phase separator by the carrier waves to lower the I and Q signals to a base band (base band signals);

a carrier wave restoration unit to eliminate frequency offsets and phase noises of the carrier waves from the base band signals output by the complex multiplier and to provide carrier waves at the feed back point for feeding back to the complex multiplier;

a channel equalizer to eliminate an inter-symbol interference due to multi-paths from the signal restored by the carrier wave restoration unit; and

a channel decoder to eliminate channel noise from the signal output by the channel equalizer, and then to recover a synchronous signal from the base band I signal in which the synchronous signal was inserted in time of transmission, and to restore the transmitted symbol, or symbol data using the synchronous signal.

18. A channel management apparatus, comprising:

an estimation unit to estimate an intensity and a signal-to-noise ratio (SNR) of broadcast signals received via a plurality of physical channels (PCT channels) in a channel memory mode;

a determination unit to determine reception quality of the respective plurality of PCT channels, in consideration of both the estimated intensity and SNR of the broadcast signals; and

an assignment unit to assign the plurality of PCT channels to a virtual channel (VCT channel) according to a predetermined rule with respect to a reception quality of the plurality of PCT channels.

19. The channel management apparatus of claim 18, wherein the estimation unit comprises:

an auto gain control amplifier to perform automatic gain control on the broadcast signal with the intermediate frequency to amplify the broadcast signal to a fixed amplitude irrespective of the signal intensity;

a signal intensity estimator to estimate the intensity of the broadcasts signals;

an analog-to-digital converter to convert the broadcast signal in the analog form amplified by the auto gain control amplifier into a digital broadcast signal;

a digital modulator to demodulate the digital broadcast signal output by the analog-to-digital converter to restore a synchronous signal and then restore a transmitted symbol using the synchronous symbol; and

a signal-to-noise ratio unit to calculate the signal-to-noise of the symbol output by the digital modulator.

20. A computer readable medium to perform a method of channel management in a broadcast receiver, the method comprising:

estimating an intensity and a signal-to-noise ratio (SNR) of broadcast signals received via a plurality of physical channels (PCT channels) in a channel memory mode;

determining reception quality of the respective plurality of PCT channels, in consideration of both the estimated intensity and SNR of the broadcast signals; and

assigning the plurality of PCT channels to a virtual channel (VCT channel) according to a predetermined rule with respect to a reception quality of the plurality of PCT channels.

21. A computer readable medium to perform a method of channel management in a broadcast receiver, the method comprising:

evaluating signal intensities and signal-to-noise ratios of broadcast signals carried on a plurality of physical channels (PCT channels); and

assigning a reception channel, among the plurality of physical channels (PCT channels) evaluated, having the best quality to a virtual channel (VCT channel) in a multi-frequency network (MFN).