Pilot Symbol Patterns for Transmission via a Plurality of Antennas

摘要

A method and apparatus for improving channel estimation within an OFDM communication system. Channel estimation in OFDM is usually performed with the aid of pilot symbols. The pilot symbols are typically spaced in time and frequency. The set of frequencies and times at which pilot symbols are inserted is referred to as a pilot pattern. In some cases, the pilot pattern is a diagonal-shaped lattice, either regular or irregular. The method first interpolates in the direction of larger coherence (time or frequency). Using these measurements, the density of pilot symbols in the direction of faster change will be increased thereby improving channel estimation without increasing overhead. As such, the results of the first interpolating step can then be used to assist the interpolation in the dimension of smaller coherence (time or frequency).

主权项

1. An apparatus comprising:
a processor, wherein the processor is configured to control transmissions through a plurality of antennas, wherein the processor is configured to:
insert a plurality of collections of pilot symbols on the plurality of antennas, respectively, wherein the plurality of collections of pilot symbols are inserted respectively in a plurality of sets of resource locations of a subframe;
wherein the subframe spans a plurality of OFDM symbol durations in time and a plurality of subcarriers in frequency,wherein, for each antenna of the plurality of antennas, the resource locations of the respective set are scattered in the subframe,wherein the sets of resource locations belonging to said plurality of sets are disjoint,wherein, for each antenna of the plurality of antennas, the respective set of resource locations includes at least two resource locations that are either frequency adjacent or time adjacent to corresponding resource locations in the set of resource locations corresponding to another one of the plurality of antennas; andtransmit the subframe, wherein said transmitting the subframe includes transmitting the plurality of collections of pilot symbols respectively within the plurality of sets of resource locations and respectively through the plurality of antennas.