The present invention discloses a channel equalization-free single-carrier broadband transmission method, including the following steps: obtaining a number of temporal-resolvable multi-paths, and delays and channel gain vectors corresponding to the multi-paths based on a channel impulse response; deliberately introducing, by a transmitter, a corresponding delay for a symbol sequence, so as to perform delay compensation, so that all multi-path signal components arrive at a receiver simultaneously and constructively after propagating over a time-dispersive channel, thereby avoiding inter-symbol interference in broadband transmission; and utilizing, by the transmitter, multiple antennas to perform path-based beamforming design. A time-dispersive channel can be transformed into a frequency-flat channel by means of the path-based ZF beamforming and delay alignment modulation. The present invention further proposes a channel equalization-free single-carrier broadband transmission system. In the present invention, with delay alignment modulation and the path-based beamforming, the issue of inter-symbol interference in broadband communications is resolved, without requiring the channel equalization or multi-carrier transmission, thereby achieving the low-complexity single-carrier broadband communication.

Aspects of the present invention provide additional MAC functionality to support the PHY features of a wireless communication system framework. The additional MAC functionality aids in enabling feedback from wireless terminals to base stations. In some aspects of the invention the feedback is provided on an allocated feedback channel. In other aspects of the invention the feedback is provided by MAC protocol data units (PDU) in a header, mini-header, or subheader. The feedback may be transmitted from the wireless terminal to the base station autonomously by the wireless terminal or in response to an indication from the base station that feedback is requested. Aspects of the invention also provide for allocating feedback resources to form a dedicated feedback channel. One or more of these enhancements is included in a given implementation. Base stations and wireless terminals are also described upon which methods described herein can be implemented.

In this disclosure, methods for pre-compensation of the phase shifting error, and apparatuses for the same are disclosed. In one example, a device performs precoding of a digital signal, while acquiring information on an error caused by a phase shifting of the precoding. Then, the device performs phase compensation on the digital signal based on the acquired information. Here, the phase compensation may compensate different amount of phase based on an amount of the phase shifting of the precoding. This phase compensated-digital signal is converted to an analog signal, and is transmitted to a receiver.

System, devices, and methods facilitate determining positioning using distributed antenna system with service availability monitoring. Positioning methods include network based methods and handset assisted methods in addition to a monitoring system to report any service outage and possible location information loss. The system provides location information also at handset only level through application or apps and operating systems with online and off-line access to location database data. A combined monitoring system that monitors antenna output power for mobile coverage and service availability helps also in monitoring the availability of the localization system and dynamic update of lookup information. Monitoring system provides also asset tracking and service analytics features for the active or passive distributed antenna system.

Provided is a method for transmitting a sounding reference signal by a terminal, and a terminal using the method. The method comprises the following steps: receiving carrier information indicating the carrier via which a sounding reference signal is to be transmitted; receiving a physical downlink shared channel (PDSCH) through a first downlink component carrier; and transmitting a sounding reference signal through a second downlink component carrier, wherein the second downlink component carrier is determined based on the carrier information.

A method and apparatus for increasing the data rate and providing antenna diversity using multiple transmit antennas utilize a set of bits of a digital signal to generate a codeword. Delay elements may be provided in antenna output channels, or, with suitable code construction, delay may be omitted. n signals represent n symbols of a codeword are transmitted with n different transmit antennas. At the receiver, the noisy received sequence is decoded. The parallel transmission and channel coding enables an increase the data rate over previous techniques, and recovery even under fading conditions. The channel coding may be concatenated with error correction codes under appropriate conditions.

A simple block coding arrangement is created with symbols transmitted over a plurality of transmit channels, in connection with coding that comprises only simple arithmetic operations, such as negation and conjugation. The diversity created by the transmitter utilizes space diversity and either time or frequency diversity. Space diversity is effected by redundantly transmitting over a plurality of antennas, time diversity is effected by redundantly transmitting at different times, and frequency diversity is effected by redundantly transmitting at different frequencies: Illustratively, using two transmit antennas and a single receive antenna, one of the disclosed embodiments provides the same diversity gain as the maximal-ratio receiver combining (MRRC) scheme with one transmit antenna and two receive antennas. The principles of this invention are applicable to arrangements with more than two antennas, and an illustrative embodiment is disclosed using the same space block code with two transmit and two receive antennas.

Systems and methods are disclosed that facilitate creating antenna ports to correspond to two or more groups of user equipment. The systems and methods can organize two or more groups of user equipment and signal to each of the two or more groups a respective antenna port. The systems and methods can further communicate mapping information, a reference signal, or delay related to a linear combination in order to identify antenna ports. Based on such communicated information, the reference signal can be decoded in order to identify each antenna port.

Devices, systems, and methods are presented for a wireless base station to assign dynamically a plurality of radio transceiver chains among a varying number of wireless channels. In this manner, the communication system including the wireless base station may transition between a range extension mode and an enhanced capacity mode. In the range extension mode, a system is configured for maximum communication range with Subscriber Stations that are relatively distant from the radio transceiver chains, although communication is still possible with nearby Subscriber Stations. In the enhanced capacity mode, the system is configured for maximum communication throughput with Subscriber Stations that are relatively near to the radio transceiver chains, whereas communication with relatively distant Subscriber Stations will be either terminated or at least non-optimized.

Antenna arrays with signal feeds connected to switchable delay lines are provided. In certain embodiments, a mobile device includes a transceiver configured to generate a radio frequency input signal, a front end system including a power amplifier configured to amplify the radio frequency input signal to generate a radio frequency output signal, and an antenna array including a first antenna configured to transmit the radio frequency output signal. The first antenna is configured to receive the radio frequency output signal through a selected delay line chosen from a plurality of delay lines.