摘要:
A Viterbi decoding system interprets bits in received QAM constellations as many-valued parameters rather than binary valued parameters. It performs the Viterbi algorithm using these many-valued parameters to provide results superior to hard decision decoding. Rather than applying a hard 0-1 function to the QAM data, the system uses a non-stepped linear or curved transfer function to assign values to the bits. In another aspect, a system differentiates between data bits based on their estimated reliability, giving more emphasis to decoding reliable bits than unreliable bits using any of a variety of techniques. By differentiating between god and bad bits and de-emphasizing or ignoring unreliable bits, the system can provide a significant reduction in uncorrectable errors and packet loss.
摘要:
A Viterbi decoding system interprets bits in received QAM constellations as many-valued parameters rather than binary valued parameters. It performs the Viterbi algorithm using these many-valued parameters to provide results superior to hard decision decoding. Rather than applying a hard 0-1 function to the QAM data, the system uses a non-stepped linear or curved transfer function to assign values to the bits. In another aspect, a system differentiates between data bits based on their estimated reliability, giving more emphasis to decoding reliable bits than unreliable bits using any of a variety of techniques. By differentiating between good and bad bits and de-emphasizing or ignoring unreliable bits, the system can provide a significant reduction in uncorrectable errors and packet loss.
摘要:
A Viterbi decoding system interprets bits in received QAM constellations as many-valued parameters rather than binary valued parameters. It performs the Viterbi algorithm using these many-valued parameters to provide results superior to hard decision decoding. Rather than applying a hard 0-1 function to the QAM data, the system uses a non-stepped linear or curved transfer function to assign values to the bits. In another aspect, a system differentiates between data bits based on their estimated reliability, giving more emphasis to decoding reliable bits than unreliable bits using any of a variety of techniques. By differentiating between god and bad bits and de-emphasizing or ignoring unreliable bits, the system can provide a significant reduction in uncorrectable errors and packet loss.
摘要:
A Viterbi decoding system interprets bits in received QAM constellations as many-valued parameters rather than binary valued parameters. It performs the Viterbi algorithm using these many-valued parameters to provide results superior to hard decision decoding. Rather than applying a hard 0-1 function to the QAM data, the system uses a non-stepped linear or curved transfer function to assign values to the bits. In another aspect, a system differentiates between data bits based on their estimated reliability, giving more emphasis to decoding reliable bits than unreliable bits using any of a variety of techniques. By differentiating between god and bad bits and de-emphasizing or ignoring unreliable bits, the system can provide a significant reduction in uncorrectable errors and packet loss.
摘要:
In some wireless local area networks (WLANs), signals of different modulation types and rates can be received. To operate optimally, the gain of an amplifier in a receiver can be set based on a specific modulation type and rate. For example, the gain of a receive path amplifier can be changed based on one or more unique identifying characteristics in a received data packet. Once the unique identifying characteristics are located, they can be analyzed to determine which modulation type and rate are represented. The appropriate gain of the amplifier can be set based on the modulation type and rate. Advantageously, subsequent data symbols can be amplified with the set gain, thereby ensuring that the receiver optimally receives those data symbols.
摘要:
A Viterbi decoding system interprets bits in received QAM constellations as many-valued parameters rather than binary valued parameters. It performs the Viterbi algorithm using these many-valued parameters to provide results superior to hard decision decoding. Rather than applying a hard 0-1 function to the QAM data, the system uses a non-stepped linear or curved transfer function to assign values to the bits. This results in performance superior to pure hard decision decoding and approaches that of soft decision decoding; moreover, it is applicable in many situations where soft decision decoding cannot be used.
摘要:
The present invention provides a method of and an apparatus for changing the gain of a receive path amplifier during the middle of a packet transmission, and particularly changing the gain during a guard interval between a symbol with encoding bits disposed therein and a subsequent data symbol encoded in a manner corresponding to the encoding bits.
摘要:
A radio communication device is tested by forwarding relevant signal characteristic data derived at the physical (PHY) layer to the media access control (MAC) layer for processing, analysis and feedback to the radio circuit to improve performance. The relevant signal characteristics are forwarded to the MAC within (appended to) a data packet. Thus, the relevant signal characteristic is forwarded to the MAC along an existing data path (a path originally designed to transfer the receive frame only, but now transfers the combined receive frame with the attached radio characteristic). The radio characteristic may be used for testing and/or tuning the radio circuit. In one embodiment, the radio characteristic is a frequency domain representation of a received signal. The radio is tuned based on a channel estimate derived from comparison of frequency domain representations of transmitted and received signals.
摘要:
A dual band radio is constructed using a primary and secondary transceiver. The primary transceiver is a complete radio that is operational in a stand alone configuration. The secondary transceiver is a not a complete radio and is configured to re-use components such as fine gain control and fine frequency stepping of the primary transceiver to produce operational frequencies of the secondary transceiver. The primary transceiver acts like an intermediate frequency device for the secondary transceiver. Switches are utilized to divert signals to/from the primary transceiver from/to the secondary transceiver. The switches are also configured to act as gain control devices. Antennas are selected using either wideband or narrowband antenna switches that are configured as a diode bridge having high impedance at operational frequencies on control lines that bias the diodes.
摘要:
A radio communication device is tested by forwarding relevant signal characteristic data derived at the physical (PHY) layer to the media access control (MAC) layer for processing, analysis and feedback to the radio circuit to improve performance. The relevant signal characteristics are forwarded to the MAC within (appended to) a data packet. Thus, the relevant signal characteristic is forwarded to the MAC along an existing data path (a path originally designed to transfer the receive frame only, but now transfers the combined receive frame with the attached radio characteristic). The radio characteristic may be used for testing and/or tuning the radio circuit. In one embodiment, the radio characteristic is a frequency domain representation of a received signal. The radio is tuned based on a channel estimate derived from comparison of frequency domain representations of transmitted and received signals.