A method and apparatus for allowing a UE to transmit uplink signals using a MIMO scheme are disclosed. In order to maintain good Peak power to Average Power Ratio (PAPR) or Cubic Metric (CM) properties when the UE transmits uplink signals using the MIMO scheme, the UE uses a precoding scheme based on a precoding matrix established in a manner that one layer is transmitted to each antenna in specific rank transmission.

Method and apparatus for transmitting uplink signals using multi-antenna

The present invention relates to a method in which a base station transmits a downlink signal using 8 antennas may comprise the steps of: mapping a downlink signal to N (1≦N≦4) layers; precoding the signal mapped to the N layers, by using a specific precoding matrix selected from a pre-stored codebook; subjecting the precoded signal to processing for OFDM symbol generation; and transmitting OFDM symbols through 8 antennas. The pre-stored codebook may comprise precoding matrices for the respective ranks corresponding to N, the pre-stored codebook may consist of 16 codebook indexes, and a portion of the precoding matrices for high ranks in the 16 codebook indexes may be generated from the precoding matrices for low ranks.

Method and device for codebook generation and downlink signal transmission in a wireless communication system supporting multiple antennas

A multi-antenna spectrum sharing scheme is proposed based on primary activity. To maximize the cognitive system performance, two spectrum sharing optimization algorithms are designed, respectively for overlay and underlay. Simulation results show that the new spectrum sharing optimization algorithm improve the cognitive system performance with multi-antenna on the premise of protecting primary users.

Spectrum Sharing under Spectrum Overlay and Underlay with Multi-antenna

Standards development organizations around the world are making rapid advances in adopting MIMO-OFDM as the technology of choice for emerging broadband wireless standards. These include IEEE 802.11n - the next generation standard for wireless local networking, IEEE 802.16e - a new standard for metropolitan area networks, and 3 GPP Long Term Evolution (LTE) - the next generation standard for cellular networking. When multiple antennas are deployed at the transmitter, they can be used to increase data rates and/or enhance link robustness. Data rates can be increased by using space division multiplexing, which requires standardization. Link robustness can also be enhanced through transmit beamforming, which requires channel state information at the transmitter. FDD systems generally require standardization, but TDD systems also benefit from standardization. Transmit diversity techniques also enhance link robustness. However, some transmit diversity techniques require standardization (such as space time block coding), whereas some do not (such as delay diversity). In this tutorial, we will discuss the various flavors of MIMO-OFDM that are being standardized in 802.11n, 802.16e, and LTE. We will describe in detail the similarities and differences of these systems. For example, 802.11n is a TDD based system and only supports one user in the channel at any given time. LTE, on the other hand, is primarily an FDD based system, and aims to support multiple users in the channel at any given time. Hence, the concept of centralized control with multi-user MIMO is being developed within LTE and 802.16e, whereas 802.11n with decentralized control only supports single-user MIMO. However, space division multiplexing is similar across 802.11n, 802.16e, and LTE.

S.A. Mujtaba

Papers

Standardization of MIMO-OFDM Technology