Telefonaktiebolaget Lm Ericsson (publ)

Svante Signell

Erik Bengt Dahlman

Johan Nyström

Göran N Klang

Pàl Frenger

Thorsten Schier

Peter Larsson

Nianxiong Tan

Bengt Erik Jonsson

Helge Stenstrom

Pål Frenger

David Astely

Pál Frenger

Joakim Karl Olof Bergström

Thorsten Shier

Göran Klang

A set of different pilot structures are designed for use in different environments and/or different user behaviours that are expected to occur in a cell. The radio conditions for a user are estimated. Each user is then assigned an area (A-E) in resource space for its communication, which has a suitable pilot configuration. In one embodiment, the entire resource space is provided with different pilot structures in different parts (A-D) In advance and allocation of resources to the users are then performed in order to match estimated radio conditions to the provided pilot structure. In another embodiment, allocation is performed first, and then the actual pilot structure is adapted within the allocated resource space area to suit the environmental conditions.

Method and apparatus for allocating a pilot signal adapted to the channel characteristics

A set of different pilot structures are designed for use in different environments and/or different user behaviours that are expected to occur in a cell. The radio conditions for a user are estimated. Each user is then assigned an area (A-E) in resource space for its communication, which has a suitable pilot configuration. In one embodiment, the entire resource space is provided with different pilot structures in different parts (A-D). In advance and allocation of resources to the users are then performed in order to match estimated radio conditions to the provided pilot structure. In another embodiment, allocation is performed first, and then the actual pilot structure is adapted within the allocated resource space area to suit the environmental conditions.

A set of different pilot structures are designed for use in different environments and/or different user behaviors that are expected to occur in a cell. The radio conditions for a user are estimated. Each user is then assigned an area (A-E) in resource space for its communication, which has a suitable pilot configuration. In one embodiment, the entire resource space is provided with different pilot structures in different parts (A-D) In advance and allocation of resources to the users are then performed in order to match estimated radio conditions to the provided pilot structure. In another embodiment, allocation is performed first, and then the actual pilot structure is adapted within the allocated resource space area to suit the environmental conditions.

The technology downloads and upgrades terminal software of a communications device over-the-air in a efficient and fail-safe manner. The communication device is provided with radio software from a server via a wireless network including a number of access networks. A download is initiated of radio software designed for a first of two different radio access technologies of the communication device. One of the two radio access technologies of the communication device is selected for downloading the software. The radio software is downloaded via the selected available radio access technology. The radio software designed for the first radio access technology is stored in memory.

Downloading and upgrading terminal software over the air of a wireless device

In a method and system for configuring an antenna for line of sight (LOS) communication procedures are implemented for providing low error rates at moderate transmission power. The antenna is configured for a particular communications distance over line of sight links providing multiple-input multiple-output communication links, including radio links and optical wireless communications links.

Method and system of communications for high data rate transmission

Communication in a MIMO network is optimized by selecting a first set of users comprising at least one user, selecting a second set of users not comprised in the first set, adapting communication parameters for the first set of users according to a first principle suitable, e.g. SVD, adapting communication parameters for the second set of users according to a second principle, e.g. opportunistic MIMO, and transmitting to the first set of user terminals according to the first communication parameters and to the second set of user terminals according to the second communication parameters. In this way, communication with one or a few users can be optimized while network resources can be used in an efficient way also for other users.

Method and apparatus in a MIMO based communication system

A down-converter converts an amplitude modulated high frequency signal into a low frequency or baseband signal. A first mixer ( ) mixes the high frequency signal into a composite signal having an in-phase component and a quadrature component. A complex bandpass filter ( ) bandwidth limits the composite signal into a bandwidth limited signal with an in-phase component and a quadrature component. A second mixer ( ) mixes the bandwidth limited signal into an intermediate signal with an in-phase component and a quadrature component, and an adder ( ) adds one component of the intermediate signal to the other. A similar up-converter performs the reverse process.

Down/up-conversion apparatus and method

A base station in a radio telecommunication system, transforms real digital wideband high-frequency signals into a set of complex digital baseband signals and vice versa. The base station receives a set of complex digital baseband signals having an &ldquo;I&rdquo; and a &ldquo;Q&rdquo; components. A portion of these signals are modulated and then converted into complex digital high-frequency signals. The complex digital high-frequency signals are then filtered via bilinear digital ladder bandpass filters to retrieve real digital narrowband high-frequency signals. The outputs of these filters are the same corresponding &ldquo;I&rdquo; and &ldquo;Q&rdquo; components at the narrowband frequencies. These signals are further combined to form real digital wideband high-frequency signals. Finally, the combined signals are converted through a D/A converter to real analog wideband high-frequency bandpass signals.

Signal transformation method and apparatus

A complex switched capacitor filter is formed by selecting an analog baseband prototype filter with the desired filter characteristics. This prototype is converted into a corresponding real switched capacitor filter, and finally the real switched capacitor filter is converted into a complex switched capacitor filter by replacing each element of real filter by a frequency shifted complex counterpart.

Complex switched capacitor filter and designing method for such a filter

A base station in a radio communication system uses complex bandpass filters &OHgr;,, &OHgr;,, . . . ,&OHgr;,and down-sampling to channelize a wideband signal containing many channels or channel groups.

D/A-conversion of a Gray coded digital input signal is performed according to an inventive recursive Gray code-to-analog conversion algorithm. According to the recursive algorithm, the Gray code bits of the digital input are successively applied in the recursions of the algorithm, one Gray code bit for each recursion, and the analog output signal is generated by recursively updating an intermediate signal. In each recursion, the intermediate signal is selectively inverted in dependence on the particular Gray code bit that is applied in the recursion. The selective inversion of the intermediate signal is an inherent property of the Gray code-to-analog algorithm, and it is a key factor to reduce the accumulation of errors in a D/A-conversion. In a D/A-converter architecture based on the algorithm, the accumulation of offset errors will be low. Furthermore, the fact that the signal inversion is digitally controlled enables high precision implementations, further improving the performance of the D/A-converter.

Digital-to-analog conversion of LSB-first type using selective inversion

A desired programmable complex analog bandpass filter is replaced by a 'black box' that receives an analog continuous-time signal and delivers an analog continuous-time signal, just as the analog filter would, but internally realizes the programmability with a programmable discrete-time system. The transfer function of the 'black box' is the same as the transfer function of the analog filter. The 'black box' includes an anti-aliasing filter, an A/D-converter, a complex digital bandpass filter (16), a D/A-converter (18) and an anti-imaging filter (20).

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Vällingby, Sweden

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