Apparatus for receiving and recovering frequency shift keyed symbols
AssigneeMotorola, Inc.
InventorWeizhong Chen
Life of this patent
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Abstract
A receiver architecture includes a selectivity filter (206) for selectively passing a wanted channel and rejecting unwanted channels. The selectivity filter has a filter BT of about one-half the BT of the transmitter filter. A discriminator (208) is coupled to the selectivity filter for converting received symbols from the frequency domain to the time domain symbols. A symbol recovery processor (210) is coupled to the discriminator for recovering the symbols through a two-state maximum likelihood sequence estimation (MLSE) technique in which templates are optimized with a BT substantially less than the BT of the transmitter filter.
Claims24
A receiver architecture for receiving and recovering symbols transmitted over a frequency shift keyed (FSK) channel, the symbols transmitted using a transmitter filter having a ratio of transmission bandwidth to symbol rate of BT, where B is the filter half-bandwidth and T is the symbol time, the receiver architecture comprising:
- a selectivity filter for selectively passing the wanted channel and rejecting unwanted channels, the selectivity filter having a filter BT of about one-half the BT of the transmitter filter;
- a discriminator coupled to the selectivity filter for converting the symbols from frequency-domain symbols to time-domain symbols;
- and
- a symbol recovery processor coupled to the discriminator for recovering the symbols through a two-state maximum likelihood sequence estimation (MLSE) technique in which templates are optimized with a BT substantially less than the BT of the transmitter filter.
An integrated circuit for use in a receiver for receiving and recovering symbols transmitted over a frequency shift keyed (FSK) channel, the symbols transmitted using a transmitter filter having a ratio of transmission bandwidth to symbol rate of BT, where B is the filter half-bandwidth and T is the symbol time, the integrated circuit comprising:
- a selectivity filter for selectively passing the wanted channel and rejecting unwanted channels, the selectivity filter having a filter BT of about one-half the BT of the transmitter filter;
- a discriminator coupled to the selectivity filter for converting the symbols from frequency-domain symbols to time-domain symbols;
- and
- a symbol recovery processor coupled to the discriminator for recovering the symbols through a two-state maximum likelihood sequence estimation (MLSE) technique in which templates are optimized with a BT substantially less than the BT of the transmitter filter.
An apparatus for receiving and recovering symbols transmitted over a frequency shift keyed (FSK) channel, the symbols transmitted using a transmitter filter having a ratio of transmission bandwidth to symbol rate of BT, where B is the filter half-bandwidth and T is the symbol time, the apparatus comprising:
- a selectivity filter for selectively passing the wanted channel and rejecting unwanted channels, the selectivity filter having a filter BT of about one-half the BT of the transmitter filter;
- a discriminator coupled to the selectivity filter for converting the symbols from frequency-domain symbols to time-domain symbols;
- and
- a symbol recovery processor coupled to the discriminator for recovering the symbols through a two-state maximum likelihood sequence estimation (MLSE) technique in which templates are optimized with a BT substantially less than the BT of the transmitter filter.
A receiver for receiving and recovering symbols transmitted over a frequency shift keyed (FSK) channel, the symbols transmitted using a transmitter filter having a ratio of transmission bandwidth to symbol rate of BT, where B is the filter half-bandwidth and T is the symbol time, the receiver comprising:
- a down-converter for down-converting the wireless signal;
- a selectivity filter coupled to the down-converter for selectively passing the wanted channel and rejecting unwanted channels, the selectivity filter having a filter BT of about one-half the BT of the transmitter filter;
- a discriminator coupled to the selectivity filter for converting the symbols from frequency-domain symbols to time-domain symbols;
- and
- a symbol recovery processor coupled to the discriminator for recovering the symbols through a two-state maximum likelihood sequence estimation (MLSE) technique in which templates are optimized with a BT substantially less than the BT of the transmitter filter.
A transceiver for receiving and recovering symbols transmitted over a frequency shift keyed (FSK) channel, the symbols transmitted using a transmitter filter having a ratio of transmission bandwidth to symbol rate of BT, where B is the filter half-bandwidth and T is the symbol time, the transceiver comprising:
- a transmitter for transmitting a communication signal;
- a communications processor coupled to the transmitter for controlling the transmitter;
- and
- a receiver coupled to the communications processor for receiving the wireless signal, the receiver comprising:
- a down-converter for down-converting the wireless signal;
- a selectivity filter coupled to the down-converter for selectively passing the wanted channel and rejecting unwanted channels, the selectivity filter having a filter BT of about one-half the BT of the transmitter filter;
- a discriminator coupled to the selectivity filter for converting the symbols from frequency-domain symbols to time-domain symbols;
- and
- a symbol recovery processor coupled to the discriminator for recovering the symbols through a two-state maximum likelihood sequence estimation (MLSE) technique in which templates are optimized with a BT substantially less than the BT of the transmitter filter.
A wireless headset for a two-way portable communication device, the wireless headset for receiving and recovering symbols transmitted over a frequency shift keyed (FSK) channel, the symbols transmitted using a transmitter filter having a ratio of transmission bandwidth to symbol rate of BT, where B is the filter half-bandwidth and T is the symbol time, the wireless headset comprising:
- a first transducer for receiving a speech input from a user;
- a transmitter coupled to the first transducer for transmitting to the two-way portable communication device a communication signal comprising the speech input;
- a communications processor coupled to the transmitter for controlling the transmitter;
- a receiver coupled to the communications processor for receiving the wireless signal from the two-way portable communication device;
- and
- a second transducer coupled to the receiver for conveying to the user a message received in the digital wireless signal, and
- wherein the receiver comprises:
- a down-converter for down-converting the wireless signal;
- a selectivity filter coupled to the down-converter for selectively passing the wanted channel and rejecting unwanted channels, the selectivity filter having a filter BT of about one-half the BT of the transmitter filter;
- a discriminator coupled to the selectivity filter for converting the symbols from frequency-domain symbols to time-domain symbols;
- and
- a symbol recovery processor coupled to the discriminator for recovering the symbols through a two-state maximum likelihood sequence estimation (MLSE) technique in which templates are optimized with a BT substantially less than the BT of the transmitter filter.
Dependencies are inferred from the claim text.