US 9,088,447 B1 · Non-coherent transmission and equalization in doubly-selective MIMO channels

Abstract

A method and system realize reliable wireless communications in non-coherent multiple-input multiple-output (MIMO) doubly-selective channels. The method uses Grassmannian space-time-frequency block codes and an iterative generalized likelihood ratio test (GLRT) with a multi-dimensional basis expansion model (BEM), decision reordering, and a fixed number of surviving candidates. The computational complexity of a non-coherent MIMO equalizer becomes linear as a function of a code length and a size of a modulation alphabet. The codebook, the alphabet size, the bit labeling, and the block power are optimized using worst-case channel statistics or instantaneous channel states. The method can use soft-information feedback from error correction codes, such as low-density-parity-check codes to improve performance.

Claims17

Dependent claims

A method for communicating data symbols in a network, comprising:

transmitting, by a transmitter via a channel, data symbols using modulation of a block code for non-coherent transmission;
modeling the channel using the space-time-frequency basis expansion to represent inter-symbol interference (ISI) due to multi-path delays and inter-carrier interference (ICI) due to time-varying fading;
approximating the channel by a dominant Karhunen-Loeve transform (KLT) basis vectors, wherein a Legendre polynomial basis may be used over a time domain, and a Fourier basis may be used over a frequency domain;
and
detecting a received signal, wherein the detecting uses a generalized likelihood ratio test (GLRT) with soft-in soft-out space-time-frequency basis expansion to reproduce the data symbols, wherein a multi-dimensional basis expansion model (BEM) is used.

2 more elements

Dependencies are inferred from the claim text.

Non-coherent transmission and equalization in doubly-selective MIMO channels

Life of this patent

Non-coherent transmission and equalization in doubly-selective MIMO channels

Life of this patent

Abstract

Claims17