US 8,570,982 B2 · Transmit spatial diversity for cellular single frequency networks

Abstract

Multiple-In Multiple-Out (MIMO) techniques are used to increase spectral efficiency of a cellular single frequency network. In some embodiments with single transmit antenna per cell, multiple data streams are transmitted from multiple cells, one data stream per set of transmit antennae. The mapping of streams to antenna sets is permuted in time. In this way, user equipment devices (UEs) at cell edges benefit from MIMO, and UEs near cell centers benefit from high carrier-to-interference (C/I) ratio of the signal. In some embodiments, each stream is concurrently transmitted on base layer of a hierarchically modulated signal from one set, and on enhancement layer of a hierarchically modulated signal from another set. The mapping of sets to streams is permuted in time. The UEs at cell edges benefit from MIMO, and the UEs near cell centers benefit from the high C/I to decode both streams from the base and enhancement layers.

Claims40

Dependent claims

A method for transmitting data in a cellular communications system with transmit spatial diversity, the method comprising:

selecting at least one antenna from each sector of a plurality of sectors to form a transmit antenna set of a plurality of L transmit antenna sets, wherein L is an integer greater than one;
assigning for a first period, each of a plurality of L data streams to a first different transmit antenna set of the plurality of L transmit antenna sets, resulting in a first distribution of data streams among transmit antenna sets;
concurrently transmitting to a plurality of receivers during the first period, each of the plurality of L data streams through transmit antennae of the plurality of L transmit antenna sets according to the first distribution so that transmit antennae of said each transmit antenna set transmit during the first period the data stream assigned to said each transmit antenna set for the at least one first period;
assigning for a second period, each of the plurality of L data streams to a second different transmit antenna set of the plurality of L transmit antenna sets, resulting in a second distribution of data streams among transmit antenna sets, wherein the second distribution is different from the first distribution;
and
concurrently transmitting to the plurality of receivers during the second period, each of the plurality of L data streams through the transmit antennae of the plurality of L transmit antenna sets according to the second distribution so that transmit antennae of said each transmit antenna set transmit during the second period the data stream assigned to said each transmit antenna set for the second period.

3 more elements

A method for receiving data in a cellular communications system with transmit spatial diversity, the method comprising:

receiving a plurality of signals comprising a plurality of L data streams transmitted from a plurality of L transmit antenna sets based on a distribution of data streams among transmit antenna sets, wherein each of the plurality of L data streams has been concurrently transmitted by a first different transmit antenna set comprising a first distribution of transmit antennae from the plurality of L transmit antenna sets so that transmit antennae of said each transmit antenna set transmit during a first period the data stream assigned to said each transmit antenna set for the first period and concurrently transmitted by a second different transmit antenna set comprising a second distribution of transmit antennae from the plurality of L transmit antenna sets so that transmit antennae of said each transmit antenna set transmit during a second period the data stream assigned to said each transmit antenna set for the second period;
deriving a channel estimate for each of the plurality of signals to obtain channel estimates;
and
separating each of the plurality of L data streams from the plurality of signals using the channel estimates to generate a plurality of separated L data streams.

1 more element

An apparatus for transmitting data in a cellular communications system with transmit spatial diversity, the apparatus comprising:

means for selecting at least one antenna from each sector of a plurality of sectors to form a transmit antenna set of a plurality of L transmit antenna sets, wherein L is an integer greater than one;
means for assigning for a first period, each of a plurality of L data streams to a first different transmit antenna set of the plurality of L transmit antenna sets, resulting in a first distribution of data streams among transmit antenna sets;
means for concurrently transmitting to a plurality of receivers during the first period, each of the plurality of L data streams from the first through transmit antennae of the plurality of L transmit antenna sets according to the first distribution so that transmit antennae of said each transmit antenna set transmit during the first period the data stream assigned to said each transmit antenna set for the at least one first period;
means for assigning for a second period, each of the plurality of L data streams to a second different transmit antenna set of the plurality of L transmit antenna sets, resulting in a second distribution of data streams among transmit antenna sets, wherein the second distribution is different from the first distribution;
and
means for concurrently transmitting to the plurality of receivers during the second period, each of the plurality of L data streams through the transmit antennae of the plurality of L transmit antenna sets according to the second distribution so that transmit antennae of said each transmit antenna set transmit during the second period the data stream assigned to said each transmit antenna set for the second period.

3 more elements

An apparatus for receiving data in a cellular communications system with transmit spatial diversity, the apparatus comprising:

means for receiving a plurality of signals comprising a plurality of L data streams transmitted from a plurality of L transmit antenna sets based on a distribution of data streams among transmit antenna sets, wherein each of the plurality of L data streams has been concurrently transmitted by a first different transmit antenna set comprising a first distribution of transmit antennae from the plurality of L transmit antenna sets so that transmit antennae of said each transmit antenna set transmit during a first period the data stream assigned to said each transmit antenna set for the first period and concurrently transmitted by a second different transmit antenna set comprising a second distribution of transmit antennae from the plurality of L transmit antenna sets so that transmit antennae of said each transmit antenna set transmit during a second period the data stream assigned to said each transmit antenna set for the second period;
means for deriving a channel estimate for each of the plurality of signals to obtain channel estimates;
and
means for separating each of the plurality of L data streams from the plurality of signals using the channel estimates to generate a plurality of separated L data streams.

1 more element

An apparatus for transmitting data in a cellular communications system with transmit spatial diversity, the apparatus comprising:

a processor configured for:
selecting at least one antenna from each sector of a plurality of sectors to form a transmit antenna set of a plurality of L transmit antenna sets, wherein L is an integer greater than one;
assigning for a first period, each of a plurality of L data streams to a first different transmit antenna set of the plurality of L transmit antenna sets, resulting in a first distribution of data streams among transmit antenna sets;
concurrently transmitting to a plurality of receivers during the first period, each of the plurality of L data streams through transmit antennae of the plurality of L transmit antenna sets according to the first distribution so that transmit antennae of said each transmit antenna set transmit during the first period the data stream assigned to said each transmit antenna set for the at least one first period;
assigning for a second period, each of the plurality of L data streams to a second different transmit antenna set of the plurality of L transmit antenna sets, resulting in a second distribution of data streams among transmit antenna sets, wherein the second distribution is different from the first distribution;
and
concurrently transmitting to the plurality of receivers during the second period, each of the plurality of L data streams through the transmit antennae of the plurality of L transmit antenna sets according to the second distribution so that transmit antennae of said each transmit antenna set transmit during the second period the data stream assigned to said each transmit antenna set for the second period;
and
a memory coupled to the processor.

6 more elements

An apparatus for receiving data in a cellular communications system with transmit spatial diversity, the apparatus comprising:

a radio network transceiver for receiving a plurality of signals comprising a plurality of L data streams transmitted from a plurality of L transmit antenna sets based on a distribution of data streams among transmit antenna sets, wherein each of the plurality of L data streams has been concurrently transmitted by a first different transmit antenna set comprising a first distribution of transmit antennae from the plurality of L transmit antenna sets so that transmit antennae of said each transmit antenna set transmit during a first period the data stream assigned to said each transmit antenna set for the first period and concurrently transmitted by a second different transmit antenna set comprising a second distribution of transmit antennae from the plurality of L transmit antenna sets so that transmit antennae of said each transmit antenna set transmit during a second period the data stream assigned to said each transmit antenna set for the second period;
and
a processor for deriving a channel estimate for each of the plurality of signals to obtain channel estimates, and for separating each of the plurality of L data streams from the plurality of signals using the channel estimates to generate a plurality of separated L data streams.

A computer-readable medium storing a computer program, wherein execution of the computer program is for:

selecting at least one antenna from each sector of a plurality of sectors to form a transmit antenna set of a plurality of L transmit antenna sets, wherein L is an integer greater than one;
assigning for a first period, each of a plurality of L data streams to a first different transmit antenna set of the plurality of L transmit antenna sets, resulting in a first distribution of data streams among transmit antenna sets, wherein each of the plurality of L data streams are partitions of the data;
concurrently transmitting to a plurality of receivers during the first period, each of the plurality of L data streams through transmit antennae of the plurality of L transmit antenna sets according to the first distribution so that transmit antennae of said each transmit antenna set transmit during the first period the data stream assigned to said each transmit antenna set for the at least one first period;
assigning for a second period, each of the plurality of L data streams to a second different transmit antenna set of the plurality of L transmit antenna sets, resulting in a second distribution of data streams among transmit antenna sets, wherein the second distribution is different from the first distribution;
and
concurrently transmitting to the plurality of receivers during the second period, each of the plurality of L data streams through the transmit antennae of the plurality of L transmit antenna sets according to the second distribution so that transmit antennae of said each transmit antenna set transmit during the second period the data stream assigned to said each transmit antenna set for the second period.

3 more elements

A computer-readable medium storing a computer program, wherein execution of the computer program is for:

receiving a plurality of signals comprising a plurality of L data streams transmitted from a plurality of L transmit antenna sets based on a distribution of data streams among transmit antenna sets, wherein each of the plurality of L data streams has been concurrently transmitted by a first different transmit antenna set comprising a first distribution of transmit antennae from the plurality of L transmit antenna sets so that transmit antennae of said each transmit antenna set transmit during a first period the data stream assigned to said each transmit antenna set for the first period and concurrently transmitted by a second different transmit antenna set comprising a second distribution of transmit antennae from the plurality of L transmit antenna sets so that transmit antennae of said each transmit antenna set transmit during a second period the data stream assigned to said each transmit antenna set for the second period;
deriving a channel estimate for each of the plurality of signals to obtain channel estimates;
and
separating each of the plurality of L data streams from the plurality of signals using the channel estimates to generate a plurality of separated L data streams.

1 more element

Dependencies are inferred from the claim text.

Transmit spatial diversity for cellular single frequency networks

Life of this patent

Transmit spatial diversity for cellular single frequency networks

Life of this patent

Abstract

Claims40