摘要:
In one form of the invention, a process of sending real-time information from a sender computer (103) to a receiver computer (105) coupled to the sender computer (103) by a packet network (100) wherein packets (111,113) sometimes become lost, includes steps of directing (441) packets (111) containing the real-time information from the sender computer (103) by at least one path (119) in the packet network (100) to the receiver computer (105), and directing packets (113) containing information dependent on the real-time information from the sender computer (103) by at least one path diversity path (117) in the packet network (100) to the same receiver computer (105). Other forms of the invention encompass other processes, improved packets and packet ensembles (111,113), integrated circuits (610), chipsets (DSP 1721, MCU), computer cards (1651), information storage articles (1511,1611), systems, computers (103,105), gateways (191,193), routers (131,133), cellular telephone handsets (181,189), wireless base stations (183,187), appliances (1721,1731,1741), and packet networks (100), and other forms as disclosed and claimed.
摘要:
A transceiver (100) such as used in Discrete Multitone (DMT) modulation of digital signals for communication, such as in a DSL modem communications system, is described. The transceiver (100) includes a function (119) by way of which unloaded subchannels are encoded with a clip prevention signal. The clip prevention signal is derived to avoid clipping by an amplifier (18) after modulation into the time domain, upsampling, and filtering. The effects of the upsampling and filtering are considered in deriving the clip prevention signal, by considering the upsampling and filtering as a polyphase combination, and using the filter response for each phase. Frequency domain and time domain update alternatives are disclosed.
摘要:
A wireless receiver (UST). The receiver comprises at least one antenna (ATU) for receiving a plurality of frames (FR) in a form of a plurality of paths. Each of the plurality of frames comprises a plurality of time slots (SLN), and each of the plurality of time slots comprises a plurality of symbols. Further, each of the plurality of paths has a corresponding sample position, wherein the plurality of symbols comprise a primary synchronization code symbol (PSC). The receiver further comprises circuitry (52) for correlating a primary synchronization code across a group of the plurality of symbols and circuitry (52) for identifying a plurality of path positions within the group. Each of the plurality of path positions corresponds to a respective one of a plurality of largest-amplitude paths represented within the group as detected in response to the circuitry for correlating. The receiver further comprises circuitry (56) for defining a plurality of sub-windows. Each of the plurality of sub-windows comprises a plurality of sample positions, and each of the plurality of sub-windows includes at least one of the plurality of identified path positions. Finally, the receiver further comprises circuitry (54, 58) for combining paths selected from the sample positions within the plurality of sub-windows.
摘要:
A discrete multitone (DMT) digital subscriber loop (xDSL) telecommunication system has a transmitter portion including a bit encoder, inverse fast Fourier transform (FFT), parallel-to-serial converter, digital-to-analog converter and line driver for transmitting data signals to a twisted pair telephone line and a receiver portion including an analog-to-digital converter, serial-to-parallel converter, forward FFT and bit decoder for receiving data signals from the twisted pair telephone line. The FFT's are implemented in 19-bit precision using a fixed point 16-bit processor. At each FFT stage, the number of sign bits in the FFT input data is examined to determine whether overflow is possible during multiply and add operations. The input data is downscaled by right shifting one or two bits if overflow is possible. If downscaling occurred, the output data is rescaled after completion of the FFT operation. If overflow is not possible, no scaling is done. By using variable scaling to downscale only when necessary, better overall precision is maintained.
摘要:
The present invention provides a method of operating a base station transmitter. In one embodiment, the method includes providing a cellular downlink synchronization signal having primary and secondary portions, wherein the primary portion is common for all cells and the secondary portion is cell-specific and transmitting the cellular downlink synchronization signal. In another embodiment, the method includes providing a cellular downlink synchronization signal having primary and secondary portions wherein the primary portion employs a corresponding one of a plurality of different primary signals allocated to adjoining transmission cells. The method also includes further providing cell-specific information in the secondary portion and transmitting the cellular downlink synchronization signal. The present invention also provides a method of operating user equipment. The method includes receiving a cellular downlink synchronization signal having primary and secondary portions wherein the secondary portion provides cell-specific parameters and identifying and extracting the secondary portion.
摘要:
The present invention provides a method of operating a base station transmitter. In one embodiment, the method includes providing a cellular downlink synchronization signal having primary and secondary portions, wherein the primary portion is common for all cells and the secondary portion is cell-specific and transmitting the cellular downlink synchronization signal. In another embodiment, the method includes providing a cellular downlink synchronization signal having primary and secondary portions wherein the primary portion employs a corresponding one of a plurality of different primary signals allocated to adjoining transmission cells. The method also includes further providing cell-specific information in the secondary portion and transmitting the cellular downlink synchronization signal. The present invention also provides a method of operating user equipment. The method includes receiving a cellular downlink synchronization signal having primary and secondary portions wherein the secondary portion provides cell-specific parameters and identifying and extracting the secondary portion.
摘要:
Parallel concatenated trellis-coding modulation is accomplished by producing coded bits (21) from uncoded bits and also producing an interleaved version (22) of the coded bits from the uncoded bits. A first coded bits-to-signal mapping (mapping 1) is applied to the coded bits to produce a first output signal (S11), and a second coded bits-to-signal mapping (mapping 2) is applied to the interleaved version of the coded bits to produce a second output signal (S22), wherein the second coded bits-to-signal mapping differs from the first coded bits-to-signal mapping.
摘要:
A communication circuit (28) is designed with a signal processing circuit (370) arranged to produce a first plurality of data signals and receive a second plurality of data signals. A transmit circuit (364) is coupled to receive the first plurality of data signals and transmit each data signal of the first plurality of data signals on a respective transmit frequency in a predetermined sequence of transmit frequencies. A receive circuit (362) is coupled to receive each data signal of the second plurality of data signals from a remote transmitter on the respective transmit frequency in the predetermined sequence. The receive circuit applies the second plurality of data signals to the signal processing circuit.
摘要:
In a wireless communication receiver (31) of a wireless communication system that utilizes transmit diversity and turbo coding, symbol decisions are based at least in part on a posteriori probabilities (47, 48) produced by SISO decoders (35, 36). These probabilities are produced iteratively in alternating fashion to support the symbol decision process. The SISO decoder associated with the weakest (92) wireless communication channel goes first (93) in the iterative process.
摘要:
In a wireless communication receiver (31) of a wireless communication system that utilizes transmit diversity and turbo coding, symbol probabilities (45, 46) are generated (34) based at least in part on a posteriori output probabilities (47, 48) produced by SISO decoders (35, 36).