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DE-112012001124-B4 - Multi-antenna transmission method and system and respective mobile device

DE112012001124B4DE 112012001124 B4DE112012001124 B4DE 112012001124B4DE-112012001124-B4

Abstract

Multi-antenna transmission method for providing downlink radio coverage from a radio base station to a mobile terminal in a mobile communications network by means of a transmission system, comprising: - at least one multi-radiator transmitting antenna directed towards at least one mobile device, in particular a smart antenna or an array antenna, - at least one database associated with at least one coverage cell of the mobile communications network and containing information about the position of the mobile device; - Method means that interact with the at least one multi-radiator transmission antenna and the at least one database, wherein the method means are configured to connect a transmission direction with the position of the mobile device, wherein the transmission direction is suitable for reaching the mobile device, comprise the steps: a) Detecting the position of the mobile device; b) Storing the position in at least one database; c) Determining at least one transmission direction of at least one transmission beam from the at least one multiple-radiator transmission antenna to the mobile device, depending on the position stored in the at least one database, wherein at least one of the transmission parameters, which must be determined in order to transmit in the transmission direction in the at least one multiple-radiator transmission antenna, is linked to the stored position of the mobile device, and d) Comparing reception quality information signaled by the mobile device with the reception quality expected for the position achieved by the mobile device and stored in the database.

Inventors

  • Alessandro Striuli

Assignees

  • SISVEL TECHNOLOGY S.R.L.

Dates

Publication Date
20260513
Application Date
20120306
Priority Date
20110307

Claims (11)

  1. A multi-antenna transmission method for providing downstream radio coverage from a radio base station to a mobile terminal in a mobile communications network by means of a transmission system, comprising: - at least one multi-radiator transmitting antenna directed towards at least one mobile terminal, in particular a smart antenna or an array antenna; - at least one database associated with at least one coverage cell of the mobile communications network and containing information about the position of the mobile terminal; - means of the method, which interact with the at least one multi-radiator transmitting antenna and the at least one database, wherein the means of the method are configured to link a transmission direction with the position of the mobile terminal, wherein the transmission direction is suitable for reaching the mobile terminal, comprising the steps of: a) acquiring a position of the mobile terminal; b) storing the position in the at least one database; c) Determining at least one transmission direction of at least one transmission beam from the at least one multiple-radiator transmission antenna to the mobile device, depending on the position stored in the at least one database, wherein at least one of the transmission parameters, which must be determined in order to transmit in the transmission direction in the at least one multiple-radiator transmission antenna, is linked to the stored position of the mobile device, and d) Comparing signals transmitted by the mobile device nalized reception quality information with the reception quality expected for the position achieved by the mobile device and stored in the database.
  2. Transmission procedure according to Claim 1 , characterized in that the at least one transmission parameter includes the phase of the carrier frequency of the transmission beam in the transmission direction, which is determined by a transmission technique of the MIMO type.
  3. Transfer procedure according to Claim 1 , characterized in that step a) includes the substep of determining the position of the mobile device by a method executed by network elements.
  4. Transmission procedure according to Claim 1 , characterized in that steps b) and/or c) are performed using machine learning algorithms.
  5. Transfer procedure according to Claim 1 , characterized in that it includes the possibility of activating hand-over procedures to move the transmissions towards the mobile device from one radio channel to another, such that the transmission directions are changed in different carrier frequencies.
  6. Transmission procedure according to Claim 1 , characterized in that it includes the step of updating the database if the reception quality information signaled by the mobile device does not match the information stored in the database.
  7. Transfer procedure according to Claim 1 , characterized in that step a) includes the step of receiving information about the current position of one of the mobile devices from the mobile device.
  8. Multi-antenna transmission system for downlink radio coverage from a radio base station to a mobile terminal in a mobile communications network by means of a transmission system that includes means for implementing the method according to one of the Claims 1 until 7 includes.
  9. Mobile terminal device suitable for receiving transmissions from a multi-antenna transmission system for downlink radio coverage from a radio base station to a mobile terminal device in a mobile communications network according to Claim 8 and sets up the transfer procedure in accordance with one of the Claims 1 until 7 to implement.
  10. Mobile device according to Claim 9 , characterized in that it includes procedural means set up to interact with the database for transmission feedback information to the system about its own operation.
  11. Mobile device according to Claim 10 , characterized in that it can send information about its own current position to the transmission system when at least one of the following events occurs: a) receiving a command from the transmission system; b) transmitting a connection request on a radio service channel towards the transmission system; c) expiry of a current time interval; d) detecting a mobile cell change.

Description

The present invention relates to a method and a system for multiple antenna transmission, in particular used for providing cellular downlink coverage in a mobile communications network, and to a mobile terminal device thereof. As is well known, cellular coverage of mobile telecommunications networks has developed rapidly since its introduction to the mass market in the 1980s. Initially, these networks primarily supported voice services, but nowadays the demand for data services is increasingly important and more widespread. Technological development has thus been spurred by the constant demand for performance improvements in network transmission speed and capacity. Standardization is now progressing at a speed that was unusual for the telecommunications sector during the last decade, but is now being incentivized by the increasing frequency range requirements of various new data applications, leading to the introduction of new technologies that enable better performance. The increasing demand for frequency bands, however, clashes with the limited radio resources. In fact, the radio frequencies used for modern telecommunications services are limited and rigidly allocated to a few operators who cannot use frequencies for which they do not have a license. Therefore, it is generally not possible to increase frequency allocation to cope with the continuous increase in traffic. The technical solutions that can be adopted to increase network capacity given a specific available radio frequency range can be classified into two main categories: - Techniques that allow for greater frequency reuse, typically by increasing the number of cells (which therefore become smaller and smaller, so much so that they are also known as "pico-cellular"coverings); - Techniques that employ more efficient transmission and modulation methods that allow the transmission of larger amounts of data to the available radio frequency range. However, the number of cells and transmission efficiency are both subject to physical and economic limitations. The limitations of pico-cellular coverage arise from interference between cells, which increases as the cells are located closer together; furthermore, the increasing number of radio base stations leads to significantly higher transmission costs due to the connections that must be provided between the radio base station and the transport network access points. Theoretically, the higher the number of cells in a cellular network, the greater the need for a complex transmission distribution infrastructure to connect the radio base stations, causing the cellular network to tend to resemble a fixed-line transmission network. Network management costs also increase due to the number of radio base stations. Nevertheless, economic limits depend on considerations of economic advantages and are therefore not absolute theoretical limits. In contrast, technical limitations characterize every given technology in an absolute way. The achievable transmission efficiency limits are determined by the fact that extreme modulations degrade the signal-to-noise ratio (SNR) until it becomes unsustainable for ensuring the accurate operation of the system. Therefore, intensive studies are being conducted to optimize transmission technologies that focus on utilizing the largest portion of the available radio frequency range. To provide an answer to the problems described above, MIMO techniques and techniques based on the use of "vector antennas" (also known as "smart antennas") or "multi-antenna systems" or "multi-radiator systems" have been developed over time. In particular, MIMO techniques express a concept first proposed by Arogyaswami Paulraj and Thomas Kailath in 1994: these are transmission/receive techniques based on the use of multiple antenna transmitters and receivers. In a typical embodiment, MIMO transmission generates "N" signals on the same carrier frequency, whose signals, however, are arranged at "spatial" intervals from one another. Spatial separation is achieved by radiating signals from several antennas arranged in correspondingly different positions and by receiving the signals using a receiving system composed of several antennas that are also arranged at spatial intervals from one another. This is based on the hypothesis that the different propagation paths between the transmitting antennas and the receiving antennas have different transmission functions due to the multiple propagation paths. The fact that a signal generated by a transmission antenna propagates to a receiving antenna through a certain number of multiple propagation paths is generally known as "multipath". This "multipath" propagation condition is typically found in cellular coverage in urban environments. Due to the multipath effect, the signal arriving at a receiving antenna is the sum of a certain number of signals, one for each different path the original signal can take to reach the receiving point. The different signals differ p