Abstract:
A method, a computer program and a system for allocating radio resources are provided for a TDMA cellular telecommunications system which applies spatial diversity and cell-specific radio frequency bands. The system for allocating the radio resources includes a frequency allocating network element for allocating radio frequency bands to at least two radio cells located within a reuse distance from each other, at least one overlap region being formed between the radio frequency bands, the at least one overlap region being reserved for a simultaneous use in the same transmission direction of the at least two radio cells. The invention provides a frequency reuse capability for radio cells located within a reuse distance from each other.
Abstract:
The present invention proposes a device (1) for processing received signals transmitted via a transmission channel (4), said device comprising obtaining means (2a) adapted to obtain an estimated response function (h+e) of said transmission channel (4), based on said received signals (y); deriving means (2b) adapted to derive and estimated variance (&dgr;2) of said received signals (y); and modifying means (2c) adapted to modify said estimated response function (h+e) by applying said estimated variance (&dgr;2) to said estimated response function (h+e), thereby obtaining a modified impulse response (h). The present invention also proposes a corresponding method.
Abstract:
The invention relates to a method for determining connection quality, and a receiver in a radio system, the receiver comprising means for decoding a received signal by the Viterbi method by means of a trellis diagram comprising a group of state points, and means for calculating state transition values for the two possible transitions in each point of the diagram. To determine advantageously the quality of the connection between a transmitter and the receiver, the inventive receiver comprises means for calculating, in each column of the trellis diagram, the maximum values for both the transitions of the points in the column, for determining the absolute value of the difference of the calculated maximum values, and means for estimating connection quality by utilizing said absolute value.
Abstract:
The invention relates to a data transmission method and radio system. In particular, the invention relates to a method and system in which both the GMSK and the m-PSK modulation methods are available for the signal to be transmitted an in which the modulation method used at a given time can be changed to another modulation method. In the solution of the invention, the m-PSK modulator of the transmitter includes a multiplier adapted to multiply the signal to be transmitted by a given coefficient making the signal constellations of the received signal similar regardless of the modulation method. Thus, the processing of the signal in the receiver becomes easier and the quality of the transmission improves in connection with m-PSK modulation.
Abstract:
The present invention proposes a signal processing device for processing received signals having been transmitted via a transmission channel, wherein said received signals (y) are supplied to an estimation means (2) adapted to estimated a channel impulse response function (h) of said transmission channel (1), with said estimation means being adapted to perform a Linear-Minimum-Mean-Square-Error-(LMMSE-) processing based on a training sequence (TR_SEQ) transmitted together with received samples contained in said received signals (y), and a noise and interference energy estimate represented by a noise and interference variance (&dgr;2) as well as an impulse response energy distribution estimate represented by an estimated parameter covariance matrix (Chh) for said channel (1). The present invention also proposes a corresponding method for signal processing.
Abstract:
In a mobile communication system, signals which are transmitted from mobile stations moving relative to a base station are subject to a Doppler effect. A technique is described for compensating for that Doppler effect by using estimated bit decisions for received bits which are sufficiently close to a zero phase offset point so as not to have been corrupted by the Doppler effect. The Doppler shift measured using these estimated bits can then be applied to bits of the signal which are further away from the zero phase offset point.
Abstract:
In a method for performing a phase comparison, and a phase comparator, two binary signals are compared using two functionally similar asynchronous state machines, which generate two output signals used for controlling a phase. A first state machine is fed a first signal to be compared, an output signal of a second state machine and a handshaking signal of the second state machine. The second state machine is fed a second signal to be compared, an output signal of the first state machine and a handshaking signal of the first state machine. The two state machines activate their respective handshaking signals after detecting activation of the signal to be compared. The handshaking signal ensures the logical operation of the phase comparator.
Abstract:
A method of detecting a call set-up burst, and a receiver, in a digital radio system, the receiver comprising a converter (304) for sampling a signal received in a given time slot, means (400) for correlating digitalized samples with a known training sequence, and means (402) for computing the energy of the correlation results obtained, means (404) for looking for the maximum values of a string of samples of a given order from the computed energies, and means (408) for averaging the maximum values found per one sample. To improve reliability of detecting a call set-up burst, the receiver comprises means (410) for averaging the energy of the other samples of the time slot per one sample, and means (412) for comparing the averaged maximum energy values with the energy values of the other samples.