Motorola Corporation

Motorola Mobility LLC

Freescale Semiconductor,inc.

Google Technology Holdings LLC

Marc Bernard De Courville

Stephanie Rouquette-Leveil

Markus Muck

Patrick Labbe

Sebastien Simoens

Alexandre Ribeiro Dias

Laurent S Mazet

David Bateman

Merouane Debbah

Lina Mroueh

Makus Muck

Sebastian Simoens

Veronique Buzenac Settineri

Jeremy Gosteau

A wireless transmitter includes a stream parser for generating a plurality of spatial streams from a digital signal and a space time block coder (STBC) for mapping each of the spatial streams to a plurality of space-time streams that each include data and a preamble for estimating a channel transfer function. The transmitter also includes a spatial mapper for spatially expanding each of the space-time streams by applying a spatial expansion matrix to data and to first training symbols used in the preamble to probe a channel experienced by the data and by applying an extension matrix to second training symbols used in the preamble to probe at least one additional dimension of the channel to enable use of beamforming to achieve range extension The spatial expansion matrix and the extension matrix form an overall matrix that has at least two orthogonal columns with different norms. The wireless transmitter also includes an analog front end for modulating the spatially expanded space-time streams onto a wireless carrier.

Method and apparatus using sounding PPDUs to provide range extension to IEEE 802.11n signals

A method is provided for transmitting a digital signal. The method includes generating a plurality of spatial streams from a digital signal and transforming the spatial streams into a plurality of space-time streams. Each of the space-time streams are cycled in the frequency domain among each of a plurality of transmit antennas. The space-time streams are wirelessly transmitted from the plurality of transmit antennas.

Spatial mapping of an OFDM signal to reduce attenuation from an individual transmit antenna in a MIMO transmitter

A transmitter comprises a block generator () which divides a data symbol stream into data symbol blocks. A divide processor () divides each block into a first set of data symbols stored in a first set buffer () and a second set of data symbols stored in a second set buffer (). A space time block encoder () codes the first set in accordance with a space time block code to generate a coded set of data symbols. A parallel processor () then creates a plurality of parallel data streams from the coded set and the second set. Each of the parallel data streams is allocated to one of a plurality of antennas (-). A plurality of parallel stream transmitters (-) transmits the parallel data streams in parallel in a communication channel from the plurality of transmit antennas (-).

Method and apparatus for transmitting and receiving a data symbol stream

Disclosed is a method and apparatus for encoding a modulated signal in a communication system. The method comprises generating an initial constellation, applying a vertical axis symmetry to the initial constellation to generate a first resulting constellation, translating the first resulting constellation to a left direction of the initial constellation to produce a left flipped constellation, applying a horizontal axis symmetry to the initial constellation to generate a second resulting constellation, translating the second resulting constellation to an up direction of the initial constellation to produce an up flipped constellation, applying a central axis symmetry to the initial constellation to generate a third resulting constellation; and translating the third resulting constellation to a left-up direction of the initial constellation to produce a left-up flipped constellation.

Method and apparatus for encoding a modulated signal in a communication system

An Orthogonal Frequency Division Multiplex (OFDM) transmitter () comprises a symbol generator () for generating a first OFDM symbol comprising user data and pilot data where the pilot data comprises a set of predetermined non-orthogonal pilot symbols. A weight generator () uses an amplitude estimator () for selecting a set of weights for the pilot data of the first OFDM symbol in response to a time domain amplitude variation characteristic of the first OFDM symbol. In particular, the peak to average power ratio may be determined. The set of weights are selected from a discrete alphabet of weights. A weight processor () determines a second OFDM symbol by weighting the pilot symbols by the set of weights. The second OFDM symbol is transmitted to a receiver without transmitting identification of the selected set of weights. The receiver may perform a blind detection of the applied weights and may compensate the received pilot symbols for the estimated weight.

Communication apparatus and a method of transmitting data therefor

An Orthogonal Frequency Division Multiplexing, OFDM, transmitter comprises a signalling data generator () which generates a set of data symbols indicative of physical layer characteristics of data transmissions from the OFDM transmitter (). A first symbol generator () and second symbol generator () generates a first and second OFDM signalling symbol by allocating the set of data symbols to subcarriers. The allocation of the physical layer data symbols to subcarriers is different for the first OFDM signalling symbol and the second OFDM signalling symbol. A data packet generator () and transmitter () generate a data packet and transmit this to an OFDM receiver (). The OFDM receiver () determines the physical layer data symbols by combining the data symbols of corresponding subcarriers of the first and second OFDM signalling symbols and uses the resulting information to decode the user data of the data packet.

Transmission of signaling information in an OFDM communication system

In an orthogonal frequency division multiplex communication system, for example a HIPERLAN/2 system, power amplifiers () of mobile terminals () are switched off when not in use, and then switched on again when a signal transmission is to be made. This conserves power, but introduces a power amplifier transient (). An access point (), i.e. a type of base station, compensates for these power amplifier transients () using a simple scalar constant gain transient correction, over a full OFDM symbol (or a plurality of OFDM symbols). The correction is updated on an OFDM symbol by symbol basis (or plurality of symbols by plurality of symbols basis).

Controlling power supply between a voltage generator, a load and a rechargeable battery

Multiple Transmit Multiple Receive Orthogonal Frequency Division Multiplexing ('OFDM') comprising generating bit streams and corresponding sets of N frequency domain carrier amplitudes ({tilde over (s)}(kN+j), 0&#x2266;j&#x2266;N&#x2212;1) modulated as OFDM symbols subsequently to be transmitted from a transmitter, where k is the OFDM symbol number and j indicates the corresponding OFDM carrier number. Affix information is inserted at the transmitter into guard intervals between consecutive time domain OFDM symbols and are used at the receiver to estimate the Channel Impulse Response (H) of the transmission channels, the estimated Channel Impulse Response (&#x124;) being used to demodulate the bit streams in the signals received at the receiver. The affix information is known to the receiver, as well as to the transmitter, and is mathematically equivalent to a vector (c) that is common to the time domain OFDM symbols multiplied by at least first weighting factors (&#x3b1;) that are different for one time domain OFDM symbol (k) than for another and second weighting factors (w(k)) that enable one of the transmit antenna means (i) to be distinguished from another.

OFDM channel estimation and tracking for multiple transmit antennas

A method of communication using Orthogonal Frequency Division Multiplexing ('OFDM') comprises generating bit streams (b&#x3b5;(0,1),n=0,1, . . . ,K&#x2212;1) and the corresponding sets of frequency domain carrier amplitudes (X(k) to X(k)), where k is the OFDM symbol number, modulated as OFDM symbols to be transmitted from a transmitter. Prefixes are inserted as guard intervals in the sample streams and the OFDM symbols are transmitted from the transmitter to a receiver. The receiver uses information from the prefixes to estimate the Channel Impulse Response (H) of the transmission channels and uses the estimated Channel Impulse Response (&#x124;) to demodulate the bit streams in the signals received. The prefixes (&#x3b1;.cto &#x3b1;.c) are deterministic and are known to the receiver as well as to the transmitter. Preferably, the prefixes (&#x3b1;.cto &#x3b1;.c) comprise a vector (P) that is common to said symbols multiplied by at least one weighting factor (&#x3b1;). The weighting factor (&#x3b1;) preferably differs from one symbol to another but the elements of a given vector (P) are multiplied by the same weighting factor. Preferably, the weighting factor (&#x3b1;) has a complex pseudo-random value.

Channel estimation using the guard interval of a multicarrier signal

A method for conversion of signals between analog and digital characterised by; applying a non-linear transfer function to an input signal, such that the relation between the quantisation levels of the converter and the input signal vary as a non-linear function of the magnitude of the input signal. The non-linear transfer function is related to the probability density function of the input signal so that larger quantisation bins of the converter correspond to less probable values of the input signal.

Method and apparatus for reduced power consumption ADC conversion

Apparatus for estimating carrier and clock frequency offsets in OFDM systems employs a maximun likelihood estimator operation on the demodulated signals. The invention has the benefit of low complexity and obviates the need for any requirement for a dedicated training channel.

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Paris, France

Marc Bernard De Courville