A 1553 data communication system having a primary data bus, a redundant data bus and a non-1553 data communication overlay system is provided. The non-1553 data communication overlay system comprises a non-1553 bus controller terminal and a non-1553 remote terminal. Each non-1553 terminal includes a non-1553 transmitter block connected to the primary bus and the redundant bus for sending non-1553 signals, a non-1553 receiver block for receiving non-1553 signals and a non-1553 receive path selection block. The non-1553 receive path selection block selectively establishes a receive path between the primary data bus or the redundant data bus and the non-1553 receiver block according to predefined receive path selection criteria. A 1553 data communication method is also provided.

Data communications system and method of data transmission

A circuit (200) for converting frequency domain information to time domain information includes an Inverse Fast Fourier Transform circuit (208) having a length of N coefficients. The Inverse Fast Fourier Transform circuit is adapted to receive input data of length N coefficients (204) and generate output data of length N coefficients (214) that are circularly shifted by m coefficients. The circuit also includes Cyclical Prefix Insertion circuit adapted to insert a cyclical prefix of length m. The Cyclical Prefix Insertion circuit includes a first switch, connected to the Inverse Fast Fourier Transform circuit, a buffer, having an input connected to the first switch and an output, the buffer having a length m, and a second switch, coupled to the first switch and to the buffer. The first and second switches selectively couple the output of the buffer and the Inverse Fast Fourier Transform circuit to an output of the second switch. The buffer is reduced to length m.

Combined inverse fast fourier transform and guard interval processing for efficient implementation of ofdm based systems

The present invention provides a method, data modulator, modem, computer readable medium and system for allocating bits to sub-carriers of data channel frequencies for spectrally efficient full-duplex transmission. Bits are allocated successively to a plurality of sub-carriers for a data channel based on minimal power consumption, a power mask for each sub-carrier, a bit capacity of each sub-carrier, and a predetermined data rate. Allocation of bits is ceased when at least one of: a predetermined total power budget has been substantially exhausted, power masks for the plurality of sub-carriers have been substantially exhausted, bit capacities for the plurality of sub-carriers have been substantially exhausted, and the predetermined data rate has been reached.

Bit and power allocation scheme for full-duplex transmission with echo cancellation in multicarrier-based modems

An interference cancellation (IC) system and method for use within a 1553 communication system comprising a data bus carrying primary signals having a 1553 component and a non-1553 component are provided. The IC system has an input port, a 1553 data extraction block and an interference cancellation circuit with an interference measurement and a cancellation block. The interference measurement block receives 1553 decoded data from the 1553 data extraction block and a sampled primary signal via the input port, and, within an impulse response block, produces an interference signal based on a 1553 impulse response system model. The cancellation block subtracts the interference signal from the sampled primary signal and produces an output signal with the 1553 component substantially cancelled. Furthermore, an IC system using adaptive filtering techniques within the impulse response block is provided. The Least Mean Squares (LMS) algorithm can be used as an adaptive filter technique.

Interference cancellation system and method using impulse response

Communication signal equalization methods and systems are disclosed. A CDMA signal having a data portion and a known portion including a known or repeated data sequence and received over a multipath communication channel represents a linear convolution between the multipath channel and a transmitted CDMA signal. A channel estimate of the communication channel is determined from the known portion, and the CDMA signal is translated into a new CDMA signal which is a cyclic convolution with the channel estimate. A frequency domain representation of the new CDMA signal is adjusted using the channel estimate to produce a frequency domain representation of an equalized signal.

Communication signal equalization systems and methods

An efficient dual time and frequency domain echo channel estimation scheme that does not need any multiplier in the implementation of its frequency domain component. The scheme applies to echo canceling in typical ADSL applications. It can be easily adapted and extended to other applications such as, but not limited to, HDSL and VDSL in which echo channel estimation and echo canceling are necessary.

Song-Nien Tang

Papers

Efficient echo channel, estimation mechanism for an ADSL echo canceller