Telefonaktiebolaget Lm Ericsson (Publ)

Farooq U Khan

Per Johan Beming

Magnus Persson

Sverker Magnusson

Stefan E J&auml;verbring

Anders Furusk&auml;r

Tawfik Lazraq

Johan P A Nystr&ouml;m

A transmitter operates using a scheme that allows receivers using either Type I Hybrid ARQ or receivers using Type II Hybrid ARQ to successfully receive and decode blocks from a common transmitter without the need for the transmitter to be informed of which scheme is being employed by the receivers.

Combined hybrid automatic retransmission request scheme

An algorithm complementary to the Selective Repeat ARQ technique is provided, that allows obsolete or otherwise superfluous packets to be safely discarded at the transmitter when using the Selective Repeat ARQ technique. Thus, clogging of ARQ buffers and deadlocking of the system can be avoided, and data transfer in mobile wireless environments using Selective Repeat ARQ can be made more efficient. In accordance with various embodiments of the algorithm, a data packet discard notification (DPDN) message is sent by the transmitter to the receiver to indicate to the receiver which packets the transmitter has discarded, so that the receiver need no longer expect to receive them. The DPDN message can be sent when the transmitter discards packets. The DPDN message can also be sent in response to a communication such as a request or negative acknowledgment that is sent by the receiver to the transmitter.

Data packet discard notification

In spread spectrum communications, a method for allocating and re-allocating channelization codes to new and existing channels in a way that makes the maximum number of codes available at a given time for channels of different rates and different spreading factors. If re-allocations are not performed, a communication system employing the invention has a higher capacity than a system employing a random allocation strategy. The invention also reduces signaling overhead for re-allocations in comparison to a random allocation strategy because fewer re-allocations are necessary.

Code allocation in CDMA

Growing community of inventors

Kiste, Sweden

Farooq U Khan