A transmitter in a wireless communication network comprises a Carrier Interferometry (CI) coder and a multicarrier modulator communicatively coupled to the CI coder. The CI coder encodes a plurality of data symbols with a plurality of CI codes to produce a plurality of CI symbol values, wherein each of the plurality of CI symbol values equals a sum of information-modulated CI code chips. Each information-modulated CI code chip equals a CI code chip multiplied by one of the plurality of data symbols. The modulator modulates each CI symbol value onto a different subcarrier frequency to produce a multicarrier signal.

Systems, methods, and baseband processors are provided to generate or process symbols in a synchronization subframe. In one example, a method includes selecting non-consecutive orthogonal frequency division multiplexing (OFDM) symbols in a synchronization subframe. A transmitter is instructed to transmit demodulation reference symbols (DM-RS) on identical first sets of subcarriers in respective OFDM symbols of the selected non-consecutive OFDM symbols for a Physical Broadcast Channel (PBCH) using a same transmit beam, wherein a gap between two subcarriers in a respective set of the identical first sets of subcarriers is three subcarriers. The transmitter is instructed to transmit the PBCH on identical second sets of subcarriers in respective OFDM symbols in the selected non-consecutive OFDM symbols.

A base station may determine a root for a sequence to be included in a signal to a UE. The base station may generate a generalized Chu sequence based on the root and scramble the generalized Chu sequence using a pseudorandom sequence that is common to a plurality of base stations. The base station may transmit the scrambled generalized Chu sequence to indicate the beginning of a downlink transmission. The UE may receive this scrambled generalized Chu sequence and determine if a beginning of a downlink transmission from a serving base station based on the received generalized Chu sequence and an expected generalized Chu sequence.

A base station may determine a root for a sequence to be included in a signal to a UE. The base station may generate a generalized Chu sequence based on the root and scramble the generalized Chu sequence using a pseudorandom sequence that is common to a plurality of base stations. The base station may transmit the scrambled generalized Chu sequence to indicate the beginning of a downlink transmission. The UE may receive this scrambled generalized Chu sequence and determine if a beginning of a downlink transmission from a serving base station based on the received generalized Chu sequence and an expected generalized Chu sequence.

In a terminal, a selecting unit selects one generation method from a plurality of generation methods for reference signals (sounding reference signals (SRSs)). A radio transmitting unit transmits reference signals (SRSs) generated in accordance with the selected generation method.

An apparatus for communication in a wireless communication network comprises a coder that encodes a set of data symbols to produce a set of coded symbols; a modulator that modulates the coded symbols onto a set of subcarrier frequencies to generate a time-domain signal comprising a sum of a set of modulated pulse waveforms; and a transmitter configured for transmitting the time-domain signal in the wireless communication network. The coder employs a matrix of spreading codes, wherein each column of the matrix multiplies a different one of the data symbols, which causes the modulator to produce a corresponding one of the set of modulated pulse waveforms. Each column of the matrix of spreading codes comprises a set of linearly increasing phases, which provides a time offset to the corresponding modulated pulse waveforms.

Facilitating assignment of root sequence index while minimizing network changes is provided herein. Operations of a system include determining an initial assignment of root sequence indexes for a group of network equipment. The operations can also include evaluating the initial assignment for first assignments that satisfy a defined criterion and second assignments that fail to satisfy the defined criterion. Based on the defined criterion, the operations can include updating the second assignments, resulting in updated second assignments. Further, the operations can include determining a revised assignment of root sequence indexes for the group of network equipment, wherein the revised assignment comprises the first assignments and the updated second assignments.

A transmitter in a wireless communication network comprises a Carrier Interferometry (CI) coder and a multicarrier modulator communicatively coupled to the CI coder. The CI coder encodes a plurality of data symbols with a plurality of CI codes to produce a plurality of CI symbol values, wherein each of the plurality of CI symbol values equals a sum of information-modulated CI code chips. Each information-modulated CI code chip equals a CI code chip multiplied by one of the plurality of data symbols. The modulator modulates each CI symbol value onto a different subcarrier frequency to produce a multicarrier signal.

An operation method of a terminal in a communication system may include: receiving, from a base station, quality of service (QoS) information for preamble groups and information on preambles belonging to each of the preamble groups; selecting one preamble group from among the preamble groups based on the QoS information and a QoS of the terminal; selecting a preamble within the one preamble group based on the information on preambles belonging to each of the preamble groups; transmitting a first message including the selected preamble to the base station; and receiving, from the base station, a second message that is a response to the first message.

A method for receiving an Orthogonal Frequency Division Multiplexing (OFDM) signal transmitted by a user device in a wireless network comprises determining which subcarrier frequencies are allocated to the user device; converting the OFDM signal to a frequency-domain values corresponding to the subcarrier frequencies; and decoding the frequency-domain values to recover data symbols encoded by the user device on the subcarrier frequencies. The decoding employs codes that are inverse to, complex-conjugate of, or complementary to a set of complex-valued codes employed by the user device to shape the OFDM signal into a superposition of cyclic-shifted pulse waveforms, wherein each of the pulse waveforms has one of the data symbols modulated thereon.