Abstract:
2117801 9421049 PCTABS00033 A method and apparatus are provided for digitizing a wide frequency bandwidth signal (105). The digitizing is accomplished by separating the wide frequency bandwidth signal (105) into a plurality of narrow frequency bandwidth signals with a plurality of filters (110). Subsequently, a converter (120) generates digitized samples of the narrow frequency bandwidth signals. Finally, a composite digitized signal (160) is generated by a combiner (150) from the digitized samples which substantially represents the wide frequency bandwidth signal (105).
Abstract:
A communication system (106) receives and codes a plurality of information signals (102-105) according to coding assignments to produce a plurality of coded baseband signals (202-205). From these signals, a simulated composite carrier signal is formed which has all the characteristics of an actual composite carrier signal which would have resulted if the plurality of coded baseband signals had been formed. The simulated composite carrier signal is analyzed to determine its peak-to-average ratio. The communication system (106) selects a different coding assignment for coding the plurality of information signals if, based on the determined peak-to-average ratio and a selection criteria, the coding assignment does not produce the desired results. The communication system (106) selects a different coding assignment until at least one or several desired coding techniques have been identified, ranks the coding techniques and makes a final selection of the coding techniques to meet the peak-to-average ratio requirements.
Abstract:
An equalization system for equalizing a corrupted signal is disclosed. The equalization system includes a complex matched filter (400) and a maximum likelihood sequence estimator (MLSE) (405) for removing the effects of phase shift, amplitude variations, intersymbol interference, etc. resulting from multi-pathing and noise contributed by the receiver front end. The system estimates a correlation signal C(t) (505) and synchronizes C(t) 505 to maximize its energy as seen on the taps of the complex matched filter (400). Taps having amplitude coefficients below a predetermined threshold are set to zero to produce a modified CIR estimate. The modified CIR estimate which has had the effects of noise virtually eliminated, is then used to construct the complex matched filter (400) and is also used as input to the MLSE (405) to produce a better equalized data signal.
Abstract:
A method and apparatus are provided for receiving electromagnetic radiation within a frequency band. The receiving is accomplished by intercepting electromagnetic radiation within the frequency band and converting the intercepted electromagnetic radiation into an electrical signal. Subsequently, a portion of the electrical signal is digitized into digitized signals. Each digitized signal represents the intercepted electromagnetic radiation within a portion of the frequency band. Finally, a composite digitized signal is generated from at least two of the digitized signals. Alternatively, the receiving process may be enhanced by intercepting first electromagnetic radiation within a portion of the frequency band and by intercepting second electromagnetic radiation within another portion of the frequency band. Subsequently, the first and the second electromagnetic radiation is combined into a composite electromagnetic radiation waveform. The composite electromagnetic radiation waveform is converted into an electrical signal which may be processed into digitized signals which form a composite digitized signal.
Abstract:
A method and apparatus are provided for digitizing a wide frequency bandwidth signal (105). The digitizing is accomplished by separating the wide frequency bandwidth signal (105) into a plurality of narrow frequency bandwidth signals with a plurality of filters (110). Subsequently, a converter (120) generates digitized samples of the narrow frequency bandwidth signals. Finally, a composite digitized signal (160) is generated by a combiner (150) from the digitized samples which substantially represents the wide frequency bandwidth signal (105).
Abstract:
A method and apparatus are provided for digitizing a wide frequency bandwidth signal (105). The digitizing is accomplished by separating the wide frequency bandwidth signal (105) into a plurality of narrow frequency bandwidth signals with a plurality of filters (110). Subsequently, a converter (120) generates digitized samples of the narrow frequency bandwidth signals. Finally, a composite digitized signal (160) is generated by a combiner (150) from the digitized samples which substantially represents the wide frequency bandwidth signal (105).
Abstract:
A communication system (106) receives and codes a plurality of information signals (102-105) according to coding assignments to produce a plurality of coded baseband signals (202-205). From these signals, a simulated composite carrier signal is formed which has all the characteristics of an actual composite carrier signal which would have resulted if the plurality of coded baseband signals had been formed. The simulated composite carrier signal is analyzed to determine its peak-to-average ratio. The communication system (106) selects a different coding assignment for coding the plurality of information signals if, based on the determined peak-to-average ratio and a selection criteria, the coding assignment does not produce the desired results. The communication system (106) selects a different coding assignment until at least one or several desired coding techniques have been identified, ranks the coding techniques and makes a final selection of the coding techniques to meet the peak-to-average ratio requirements.
Abstract:
A communication system receives and codes a plurality of information signals according to coding assignments to produce a plurality of coded baseband signals. From these signals, a simulated composite carrier signal is formed which has all the characteristics of an actual composite carrier signal which would have resulted if the plurality of coded baseband signals had been formed. The simulated composite carrier signal is analyzed to determine its peak-to-average ratio. The communication system selects a different coding assignment for coding the plurality of information signals if, based on the determined peak-to-average ratio and a selection criteria, the coding assignment does not produce the desired results. The communication system selects a different coding assignment until at least one or several desired coding techniques have been identified, ranks the coding techniques and makes a final selection of the coding techniques to meet the peak-to-average ratio requirements.
Abstract:
A communication system receives and codes a plurality of information signals according to coding assignments to produce a plurality of coded baseband signals. From these signals, a simulated composite carrier signal is formed which has all the characteristics of an actual composite carrier signal which would have resulted if the plurality of coded baseband signals had been formed. The simulated composite carrier signal is analyzed to determine its peak-to-average ratio. The communication system selects a different coding assignments for coding the plurality of information signals if, based on the determined peak-to-average ratio and a selection criteria, the coding assignment does not produce the desired results. The communication system selects a different coding assignments until at least one or several desired coding techniques have been identified, ranks the coding techniques and makes a final selection of the coding technique to meet the peak-to-average ratio requirements.
Abstract:
A communication system receives and codes a plurality of information signals according to coding assignments to produce a plurality of coded baseband signals. From these signals, a simulated composite carrier signal is formed which has all the characteristics of an actual composite carrier signal which would have resulted if the plurality of coded baseband signals had been formed. The simulated composite carrier signal is analyzed to determine its peak-to-average ratio. The communication system selects a different coding assignments for coding the plurality of information signals if, based on the determined peak-to-average ratio and a selection criteria, the coding assignment does not produce the desired results. The communication system selects a different coding assignments until at least one or several desired coding techniques have been identified, ranks the coding techniques and makes a final selection of the coding technique to meet the peak-to-average ratio requirements.