US 8,804,686 B2Granted

Signaling of precoder related information in a MIMO system

AssigneeTelefonaktiebolaget LM Ericsson (publ)

InventorsStefano Sorrentino, George Jöngren

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Abstract

Techniques are disclosed for signaling a pattern of cyclic shifts and orthogonal cover codes for use by a wireless device in multi-layer transmissions. In one example method, a signal includes B bits for identifying a reference signal is received, wherein each of several available reference signals is defined by a cyclic shift and an orthogonal cover code. The B bits are used to identify the cyclic shift and orthogonal cover code according to pre-determined tables that map each value of the B bits to a pattern of cyclic shift and orthogonal cover code combinations for a multi-layer transmission scheme. The patterns for the multi-layer transmission scheme include first and second patterns based on the same cyclic shifts, but where some, but not all, of the cyclic shifts in the first pattern are associated with the same corresponding orthogonal cover codes in the second pattern.

Claims16

Dependent claims

A method, implemented in a wireless device, for transmitting reference signals, wherein each of a plurality of available reference signals is defined by a cyclic shift and a corresponding orthogonal cover code, the method comprising:

receiving a signal including a pattern index of B bits for identifying at least one reference signal for use by the wireless device in transmissions;
and
using the pattern index to identify the cyclic shift and orthogonal cover code to be used in transmitting each of one or more spatially multiplexed data streams, according to one or more pre-determined tables that map each value of the pattern index to a pattern of cyclic shift and orthogonal cover code combinations for a first multi-layer transmission scenario, wherein the patterns define mappings of orthogonal cover codes and cyclic shifts to transmission layers as a function of the pattern index and wherein the patterns for the first multi-layer transmission scenario include a first pattern based on a set of cyclic shifts and a second pattern based on the same set of cyclic shifts, wherein each cyclic shift in the set is associated with a corresponding orthogonal cover code in the first pattern and wherein some, but not all, of the cyclic shifts in the set are associated with the same corresponding orthogonal cover codes in the second pattern;
and
transmitting each of the one or more spatially multiplexed data streams using the identified reference signal corresponding to each data stream.

2 more elements

A wireless device configured to transmit reference signals, the wireless device comprising:

a radio circuit configured to transmit each of one or more spatially multiplexed data streams using a corresponding reference signal for each data stream, wherein each of a plurality of available reference signals is defined by a cyclic shift and a corresponding orthogonal cover code, and
a processing circuit configured to
receive a signal including B bits for identifying at least one reference signal for use by the wireless device in transmissions;
and
use the B bits to identify the cyclic shift and orthogonal cover code to be used in transmitting each of one or more spatially multiplexed data streams, according to one or more pre-determined tables that map each value of the B bits to a pattern of cyclic shift and orthogonal cover code combinations for a first multi-layer transmission scenario, wherein the patterns define mappings of orthogonal cover codes and cyclic shifts to transmission layers as a function of the pattern index and wherein the patterns for the first multi-layer transmission scenario include a first pattern based on a set of cyclic shifts and a second pattern based on the same set of cyclic shifts, wherein each cyclic shift in the set is associated with a corresponding orthogonal cover code in the first pattern and wherein some, but not all, of the cyclic shifts in the set are associated with the same corresponding orthogonal cover codes in the second pattern.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/020,853Filed 4 Feb 2011 · us provisional application
Priority: 16 Feb 2010
Published: US 2011/0200135 A118 Aug 2011
Granted: 12 Aug 2014
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H04L 27/2613
Details of reference signals: structure of the reference signals
H04B 7/0413
Using two or more spaced independent antennas: mIMO systems
H04B 7/063
Feedback content: parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
H04B 7/0669
Of delayed versions of same signal: using different channel coding between antennas