Equalisation apparatus and methods
An equalizer and covariance technology, which is applied to the shaping network, transmission system, electrical components, etc. in the transmitter/receiver, and can solve the problems of system equalization, high computational complexity, and complex situations that cannot transmit antennas.
Inactive Publication Date: 2006-03-01
KK TOSHIBA
View PDF2 Cites 29 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
However, turbo equalizers using SISO equalization based on trellis or Bayesian decision rules have high computational complexity, and this computational complexity grows exponentially with the channel response length and the number of possible states / levels of the employed modulation
The simplified turbo equalization scheme described by Tuchler et al., WO 02 / 15459 and US 2002 / 0110188 considers systems with multiple receive antennas, but cannot equalize in systems with multiple transmit antennas
It should be understood that with multiple receive antennas and a single transmit antenna, each receive antenna is associated with a single channel, with multiple transmit antennas, the situation is much more complex due to the combination of signals received from different transmit antennas
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0036] Referring to FIG. 2, a block diagram 200 of a MIMO channel model is shown. A multi-stream emitter has the first n I transmit antennas 202, and transmit each symbol x at time n that constitutes the "input" to the matrix channel 206 n 1 , x n 2 ,...,x n nI . no O receiving antenna 204 to receive signal z n 1 ,z n 2 ,...,z n no available in the form of n I ×n o The "output" of the MIMO matrix channel. There is an associated channel response h between the i-th transmit antenna and the j-th receive antenna n i，j Channel. The received signal on each receive antenna also contains a noise component w n j .
[0037] in n I ×n o In a MIMO system, the MIMO equalizer aims to provide n at each signaling moment I Estimates of transmitted data symbols. Data from multiple transmit antennas are transmitted at the same or overlapping times and used at the same or overlapping frequencies, thus introducing MSI as well as ISI from scattered wideband channels. In so...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention relates to apparatus, methods and computer program code for equalisation. A soft-in-soft-out (SISO) equaliser for use in a receiver for receiving data from a transmitter configure to transmit data from a plurality of transmit antennas simultaneously is described. The equaliser comprises at least one received signal input for inputting a received signal; a plurality of likelihood value inputs, one for each transmit antenna, for inputting a plurality of decoded signal likelihood values from a SISO decoder; a processor configure to determine from the plurality of signal likelihood values an estimated mean and covariance value for a signal from each of the transmit antennas; an expected signal determiner coupled to the processor to determine an expected received signal value using the mean values; a subtractor coupled to the received signal input to subtract the expected received signal value from the received signal to provide a compensated signal; a filter coupled to the subtractor to filter the compensated signal to provide a plurality of estimated transmitted signal values, one for each the transmit antenna; a filter coefficient determiner coupled to the processor to determine coefficients of the filter using the covariance values; and an output stage coupled to the filter to output a plurality of transmitted signal likelihood values, one for each the transmit antenna, for input to the SISO decoder.
Description
technical field [0001] The present invention relates to an apparatus, method and computer program code for equalization in a communication system where a receiver receives signals from multiple transmit antennas, and in particular where the multiple transmit antennas are associated with a single transmitter. Background technique [0002] A particular problem arises in the communication link where a transmitter with multiple transmit antennas is employed, since the signals received from the different transmit antennas interfere with each other. This leads to so-called multi-stream interference (MSI) and makes decoding difficult. However, a potential advantage is a greatly increased throughput (ie, higher bit rate) of the communication link. In such a MIMO (Multiple Input Multiple Output) communication link, the "input" (to the matrix channel) is provided by multiple transmit antennas of the transmitter, and the "output" (from the matrix channel) is provided by multiple recei...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Applications(China)
IPC IPC(8): H04L1/06H04L25/03H04J99/00
CPCH04L25/03171H04L1/0618H04L2025/03414
Inventor 余梦霜
Owner KK TOSHIBA