A transmitter and a receiver for communicating data using at least two separate RF channels using channel bundling. The transmitter includes a data stream partitioner configured to partition a data stream of data to be communicated into two or more stream partitions, two or more modulators configured to each receive a stream partition and to generate modulated data from the received stream partition, and an interleaver configured to assign the modulated data generated by a modulator from a received stream partition to different RF channels for transmission.

The present invention relates to a wireless communication system, and more specifically, to a method and an apparatus for transmitting an RS (Reference Signal) from a transmission end. The present invention relates to an RS transmission method and an apparatus therefore, comprising the steps of: confirming RS resources which are defined according to each layer; and transmitting the precoded RS for the layers to a receiving end through a multiple antenna, wherein the RS resource includes a 1.sup.st index for indicating an RS resource pattern group in which the precoded RS is mapped within a resource block and a 2.sup.nd index for indicating a code resource for multiplexing the precoded RSs within the RS resource pattern group.

A node in a wireless communication network uses a modified data-to-subcarrier mapping on at least a selective basis, wherein the modified mapping effectively extends the cyclic prefix (CP) of a transmission targeted to a given receiver without extending the CP of the Orthogonal Frequency Division Multiplex (OFDM) symbol in which the transmission is conveyed. This approach allows, for example, the node to use a first or normal data-to-subcarrier mapping for transmissions that are targeted to receivers that do not need an effective increase of the CP length, while using the modified mapping for those receivers that need a longer effective CP length, e.g., because of receiver type or channel conditions.

Methods, apparatus, and systems for reducing Peak Average Power Ratio (PAPR) in signal transmissions are described. In one example aspect, a wireless communication method includes determining, for an input sequence, an output sequence corresponding to an output of a convolutional modulation between a plurality of values and an intermediate sequence. The intermediate sequence is generated by inserting a set of coefficients between coefficients of the input sequence. Each non-zero coefficient of the set of coefficients is inserted between a first adjacent coefficient and a second adjacent coefficient. Each non-zero coefficient has a power that is between a first power of the first adjacent coefficient and a second power of the second adjacent coefficient and a phase value between a first phase value of the first adjacent coefficient and a second phase value of the second adjacent coefficient. The method also includes generating a waveform using the output sequence.

An IS-OFDM system for point-to-point wireless communications that suppresses narrow-band interference comprises an IS-OFDM transmitter and an IS-OFDM receiver, wherein a transmitted signal comprises a plurality of subcarriers, and further wherein each subcarrier contains more than one and potentially all symbols transmitted in a given frame. The IS-OFDM transmitted signal is at a data rate that is equal to the data rate of the input data stream via the use of P/S converters.

A transmitter for transmitting data signals to at least one communications device over a wired network on a plurality of carriers is provided, wherein the carriers are located in frequencies being allocated by one or more radio services, wherein each of the radio services is allocated to one or a plurality of frequency bands, the transmitter comprising a symbol generator configured to generate symbols based on the data signals; a processor configured to generate copies of the symbols and to determine an allocation of the copies onto the plurality of carriers, wherein a first copy and a second copy of each symbol are allocated to carriers located in frequency bands that are allocated to different radio services; and a modulator configured to modulate the copies of the symbols on the carriers in accordance with the determined allocation.

In a method for generating a data unit for transmission via a communication channel, the data unit conforming to a first communication protocol, one or more orthogonal frequency division multiplexing (OFDM) symbols of the data unit are generated. Each OFDM symbol of the one or more OFDM symbols (i) occupies a first bandwidth, (ii) is generated with a first tone spacing, and (iii) includes a set of pilot tones. The first tone spacing is a fraction 1/N of a second tone spacing, the second tone spacing defined for the first bandwidth by a second communication protocol. The set of pilot tones includes a same number of pilot tones as defined for the first bandwidth by the second communication protocol. The data unit is generated to include the one or more OFDM symbols in a data portion of the data unit.

Various aspects of the disclosure relate to the selection and use of modulation and coding scheme (MCS) values. For example, a first MCS table may be used for a first condition and a second MCS table used for a second condition. The disclosure relates in some aspects to inter-device signaling that indicates which MCS table is to be used for communication between the devices.

Systems and techniques are described that are directed to filter frequency response shift compensation, including compensating for shifting in the rejection band of the filter. Compensation for the shifting in the rejection band can include applying a pre-distortion to attenuate edge resource units (RUs), and applying PHY Protocol Data Unit (PPDU) scheduling schemes. For example, a PPDU scheduling scheme reduce bandwidth in the channel, thereby dropping the out of band RUs. Front ends provide feedback to a respective radio, which allows that radio to apply the appropriate pre-distortion. The front ends can include one or more filters enabling frequency domain coexistence between collocated radios operating in the differing Wi-Fi bands, and a coupler that provides the feedback indicating the frequency response shift to a radio. The radio can then apply a digital pre-distortion to compensate for the shifting in the rejection band.

In one embodiment, an apparatus includes: a radio frequency (RF) front end circuit to receive and downconvert a RF signal to a second frequency signal, the RF signal comprising an orthogonal frequency division multiplexing (OFDM) transmission; a digitizer coupled to the RF front end circuit to digitize the second frequency signal to a digital signal; and a baseband processor coupled to the digitizer to process the digital signal. The baseband circuit comprises a first circuit having a first plurality of correlators having an irregular comb structure, each of the first plurality of correlators associated with a carrier frequency offset and to calculate a first correlation on a first portion of a preamble of the OFDM transmission.