Method and apparatus for measuring a radio frequency signal having program information and control information

A method of obtaining a measurement value representative of a signal level of a RF signal that includes a baseband signal modulated onto a first carrier signal having a first frequency, wherein the baseband signal includes (i) program information and (ii) control information, comprising the steps of:

• converting the RF signal to an IF signal comprising the baseband signal modulated onto a second carrier signal of a second frequency, the IF signal including (i) the program information of the baseband signal and (ii) the control information of the baseband signal;
• sampling the IF signal to obtain a digitized IF signal that is a digital representation of the baseband signal modulated onto the second carrier signal, the digitized IF signal including a first digital representation of (i) the program information of the baseband signal and (ii) the control information of the baseband signal;
• demodulating the digitized IF signal to obtain a digitized baseband signal that is a digital representation of the baseband signal, the digitized baseband signal including a second digital representation of (i) the program information of the baseband signal and (ii) the control information of the baseband signal;
• and
• determining from the digitized baseband signal the measurement value that is representative of the signal level of the RF signal.

A measurement device for obtaining a measurement value representative of a signal level of a RF signal that includes a carrier signal modulated with (i) program information and (ii) control information, comprising:

• a RF input configured to receive said RF signal;
• an analog-to-digital (A/D) converter coupled to said RF input and configured to (a) receive said RF signal from said RF input and (b) sample said RF signal to obtain a digitized RF signal that is a digital representation of said carrier signal modulated with (i) said program information and (ii) said control information;
• and
• a digital signal processing circuit coupled to said A/D converter and configured to (a) receive said digitized RF signal from said A/D converter and (b) determine from said control information included in said digitized RF signal a measurement value that is representative of said signal level of a portion of said RF signal that includes substantially only the control information.

A measurement device for obtaining a measurement value representative of a signal level of a RF signal that includes a baseband signal modulated onto a first carrier signal having a first frequency, wherein said baseband signal includes (i) program information and (ii) control information, comprising:

• a RF input configured to receive said RF signal;
• a frequency conversion circuit coupled to said RF input and configured to convert said RF signal to an IF signal comprising said baseband signal modulated onto a second carrier signal of a second frequency, said IF signal including (i) said program information of said baseband signal and (ii) said control information of said baseband signal;
• an analog-to-digital (A/D) converter coupled to said frequency conversion circuit and configured to (a) receive said IF signal from said frequency conversion circuit, and (b) sample said IF signal to obtain a digitized IF signal comprising a first plurality of digital values representative of said baseband signal modulated onto said second carrier signal, said first plurality of digital values also representative of (i) said program information of said baseband signal and (ii) said control information of said baseband signal;
• a digital signal processing circuit coupled to said A/D converter and configured to (a) receive said digitized IF signal from said A/D converter, (b) demodulate said digitized IF signal to obtain a digitized baseband signal comprising a second plurality of digital values representative of said baseband signal, said second plurality of digital values also representative of (i) said program information of said baseband signal and (ii) said control information of said baseband signal, and (c) determine from said control information included in said digitized baseband signal said measurement value that is representative of said signal level of said RF signal.