US 8,799,751 B2 · Low complexity optimal soft MIMO receiver

Abstract

A low-complexity optimal soft MIMO detector is provided for a general spatial multiplexing (SM) systems with two transmit and NR receive antennas. The computational complexity of the proposed scheme is independent from the operating signal-to-noise ratio (SNR) and grows linearly with the constellation order. It provides the optimal maximum likelihood (ML) solution through the introduction of an efficient Log-likelihood ratio (LLR) calculation method, avoiding the exhaustive search over all possible nodes. The intrinsic parallelism makes it an appropriate option for implementation on DSPs, FPGAs, or ASICs. In specific, this MIMO detection architecture is very suitable to be applied in WiMax receivers based on IEEE 802.16e/m in both downlink (subscriber station) and uplink (base station).

Claims17

Dependent claims

A method of performing a linear-complexity optimal soft Multiple-input-multiple-output (MIMO) detector, the method comprising the steps of:

calculating first and second generator matrices based upon a channel matrix;
applying the generator matrices to a received vector to generate first and second modified received vectors wherein the first modified received vector comprises an original transmitted vector and the second modified received vector comprises a flipped version of the original transmitted vector;
selecting first and second elements of the transmitted vector as child and parent symbols respectively;
determining, for both the transmitted vector and the flipped version of the transmitted vector, for each possible value of the parent symbol, a first child;
and
calculating log-likelihood ratios (LLRs) of all bits for each resulting vector.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application

13/242,808Filed 23 Sep 2011 · continuation

Priority

12 Mar 2008

Published

US 2012/0014483 A119 Jan 2012

Granted

5 Aug 2014

Term ends

Not estimatedThe source records don’t support an estimate.

Classification9 codes

H04B 7/0413
Using two or more spaced independent antennas: mIMO systems
H04L 25/03178
Arrangements for removing intersymbol interference: arrangements involving sequence estimation techniques
H04L 25/067
DC level restoring means; Bias distortion correction ; Decision circuits providing symbol by symbol detection: providing soft decisions, i.e.…
H04L 27/38
Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems: demodulator circuits; Receiver circuits

Family

Application12/046,747Parent of this continuation · filed 12 Mar 2008

US 2012/0014483 A1Pre-grant publication · published 19 Jan 2012

US 8,060,811 B2Parent of this continuation

US 2009/0232241 A1Published application

US 8,799,751 B2This patent

From the US filing history. Foreign family members aren’t listed.

Low complexity optimal soft MIMO receiver

Life of this patent

Low complexity optimal soft MIMO receiver

Life of this patent

Abstract

Claims17