A system includes: a unit configured to communicate a modulated signal via a signal interface; and at least one additional unit configured to receive the modulated signal from the unit. The at least one additional unit includes circuitry configured to remove jitter from a recovered clock signal to generate a jitter reduced clock signal that tracks long-term drift in the modulated signal, wherein the at least one additional unit is configured to generate the recovered clock signal from the modulated signal.

Methods and systems that can enable antenna selection (AS) and data bits in transmitted spatially modulated (SM) streams to be detected at a receiver using different detection methods. In example embodiments, encoding for an AS stream is done separately at a transmitter than encoding for data streams, enabling a receiver to use one type of detection for AS bits and a reduced complexity type of MIMO detection for the data bits.

A transmission apparatus includes a transmission signal generator which, in operation, generates a transmission signal having an aggregate physical layer protocol data unit (PPDU) that includes a legacy preamble, a legacy header, a non-legacy preamble, a plurality of non-legacy headers and a plurality of data fields; and a transmitter which, in operation, transmits the generated transmission signal, wherein the legacy preamble, the legacy header and the plurality of non-legacy headers are transmitted using a standard bandwidth, the non-legacy preamble and the plurality of data fields are transmitted using a variable bandwidth that is larger than the standard bandwidth and wherein a plurality of sets of each of the plurality of non-legacy headers and each of the plurality of data fields are transmitted sequentially in a time domain.

Space-time coded massive (STCM) and space-frequency coded (SFC) massive multiple-input multiple-output (MIMO) wireless communication systems and methods of making and using the same are disclosed. The STCM-MIMO system utilizes two massive MIMO antenna arrays that transmit data over two or more channel vectors to a user with at least one receive antenna. This configuration permits the system to use the asymptotic orthogonal qualities of massive MIMO pre-coding to eliminate the interference from other users' channel vectors and signals. The system also maintains the diversity of space-time codes to recover lost data through treating each transmitting massive MIMO array similarly to a 21 Alamouti space-time code. The STCM-MIMO wireless system can significantly outperform those using space-time coding techniques only. The SFC massive MIMO wireless system may be similar to the STCM-MIMO wireless system, except for the encoder block. In the exemplary SFC massive MIMO architecture, instead of spreading the code across the time slots, the code is spread across the subcarriers.

Disclosed is a transmission scheme for transmitting a first modulated signal and a second modulated signal over the same frequency at the same time. According to the transmission scheme, a precoding weight multiplying unit multiplies a baseband signal after a first mapping and a baseband signal after a second mapping by a precoding weight and outputs the first modulated signal and the second modulated signal. In the precoding weight multiplying unit, precoding weights are regularly hopped.

Disclosed herein is a method of receiving a broadcast signal. The method comprises receiving the broadcast signal; an Orthogonal Frequency Division Multiplexing (OFDM) demodulating on the received broadcast signal; parsing at least one signal frame from the demodulated broadcast signal to extract service data or service component data; converting the service data or service component data into bits; decoding the converted bits; and outputting a data stream comprising the decoded bits.

In a wireless local area network (LAN) system, a station (STA) generates an NGV PPDU, wherein the NGV PPDU comprises: a first legacy control field; a second legacy control field in which the first legacy control field is repeated; a first NGV control field; a second NGV control field in which the first NGV control field is repeated; an NGV-short training field (NGVSTF); and an NGV-long training field (NGV-LTF), and the first NGV control field is consecutive to the second legacy control field, the second NGV control field is consecutive to the first NGV control field, and the control information may include 1-bit information related to the NGV-LTF. The STA may transmit the NGV PPDU.

A transmission apparatus includes a transmission signal generator which, in operation, generates a transmission signal having an aggregate physical layer protocol data unit (PPDU) that includes a legacy preamble, a legacy header, a non-legacy preamble, a plurality of non-legacy headers and a plurality of data fields; and a transmitter which, in operation, transmits the generated transmission signal, wherein the legacy preamble, the legacy header and the plurality of non-legacy headers are transmitted using a standard bandwidth, the non-legacy preamble and the plurality of data fields are transmitted using a variable bandwidth that is larger than the standard bandwidth and wherein a plurality of sets of each of the plurality of non-legacy headers and each of the plurality of data fields are transmitted sequentially in a time domain.

Disclosed is a transmission scheme for transmitting a first modulated signal and a second modulated signal over the same frequency at the same time. According to the transmission scheme, a precoding weight multiplying unit multiplies a baseband signal after a first mapping and a baseband signal after a second mapping by a precoding weight and outputs the first modulated signal and the second modulated signal. In the precoding weight multiplying unit, precoding weights are regularly hopped.

An exemplary decoder is provided for decoding a signal received through a transmission channel in a communication system. The exemplary decoder comprises a transformation unit configured to determine a set of auxiliary channel matrices, each auxiliary channel matrix being determined by performing a linear combination of at least one of the column vectors of the channel matrix; a decomposition unit configured to determine a decomposition of each auxiliary channel matrix into an upper triangular matrix and an orthogonal matrix; a matrix selection unit configured to select at least one auxiliary channel matrix among the set of auxiliary channel matrices depending on a selection criterion related to the components of the upper triangular matrices. The decoder determines at least one estimate of vector of information symbols from an auxiliary signal and from the upper triangular matrix corresponding to a selected auxiliary channel matrix by applying a decoding algorithm.