Telefonaktiebolaget Lm Ericsson (publ)

Mikael H{umlaut Over (oo)}k

Stefan E J&auml;verbring

Peter Schramm

Carl Magnus Frodigh

Johan Nystr&ouml;m

Johan Sk&ouml;ld

Frank M&uuml;ller

In a telecommunications system, such as a cellular radio telecommunications system, transmission information, such as modulation scheme selection information, coding information or power level control commands, is efficiently conveyed from the transmitter to the receiver without increasing the bandwidth requirements and without introducing additional transmission delays. This can be accomplished by employing a data symbol phase rotation technique, wherein a sequence of data symbols, for example, a sequence of training symbols used for estimating the propagation characteristics of a given channel, are phase-rotated in accordance with a phase rotation factor that uniquely corresponds to the information being conveyed to the receiver. At the receiver, the symbols are de-rotated until the receiver recovers the training sequence. This allows the receiver to determine the phase rotation factor used to rotate the symbols at the transmitter. This, in turn, identifies the corresponding transmission information.

Signaling using phase rotation techniques in a digital communications system

A method of communicating control information in systems that support multiple modulation schemes for communicating voice or data and control information. To provide backward compatibility dedicated control channels use the modulation scheme used in current systems, for example GMSK modulation scheme. Traffic channels and associated control channels use linear modulation schemes that have the same symbol rate. The modulation scheme of the associated control channel uses a reduced signal set of the modulation scheme used for traffic channels. Also, an in-band signalling procedure is used to indicate to a receiving station the modulation type, channel coding and speech coding used for a transmitted burst.

Method for communicating information in a communication system that supports multiple modulation schemes

The present invention relates to a method and an arrangement for communicating packet information in a digital telecommunications system. Through the invention is selected a set of designated communication resources (ch -chn) from an available amount of resources. Every packet (P) is forward error correction encoded into an encoded packet (P ), via one of at least two different coding schemes (c ), prior to being transmitted to a receiving party, over the designated communication resources (ch -chn). An estimated transmission time is calculated for all combinations of coding scheme (c ) and relevant distribution (d ) of the encoded data blocks (B -B ), in the encoded packet (P ) over the set of designated communication resources (ch -chn), and the combination (c ,d ) is selected, which minimises the estimated transmission time.

Digital telecommunication system with selected combination of coding schemes and designated resources for packet transmission based on estimated transmission time

The present invention relates to a method and an arrangement for demodulating data symbols (d,-d,) having been transmitted through a communication channel, particularly a channel suffering from one or more impairments. Received signal samples ({overscore (&rgr;)}), representing the sent data symbols (d,-d,), are stored (,) and demodulated in both the forward (,) and the backward direction (,), via a demodulator/equaliser. In course of the demodulations are produced a first (S,) and a second (S,) respective set of soft values (s,; s,), which each is associated with a certain data symbol (d,). (,) From every pair of soft values (s,; s,) is then determined a joint soft value (S,), which e.g. may be utilised for deriving a resulting set of data symbols ({circumflex over (d)},-{circumflex over (d)},) or for directly decoding the payload information contained in the data symbols (d,-d,).

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Sollentuna, Sweden

Mikael H{umlaut Over (oo)}k