Cell selection in high-speed downlink packet access communication systems
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorBengt Lindoff
Life of this patent
Estimating the term…
Abstract
The usual determination of signal-to-noise ratio EC/I0 in a communication system is modified such that EC/I0 is also based on either or both of the path delay profile (PDP) and estimates of the load on a cell in the communication system. The PDP may be obtained from a path searcher in a receiver that is already needed for estimating the received signal code power of a channel such as a common pilot channel. Because PDP information is already available, it can easily be incorporated into the EC/I0 measurements.
Claims31
An apparatus in a communication system, comprising:
- a path searcher configured to determine, based on a signal from at least one cell in the communication system, a received signal code power (RSCP), a received signal strength indication (RSSI), and a path delay profile (PDP) including a plurality of path delays;
- an estimator configured to generate an estimate of a load on the at least one cell;
- and
- a control unit configured to generate at least one modified signal-to-noise-ratio (SNR) value based on the RSCP, the RSSI, and the load estimate;
- wherein the estimator is configured to generate the estimate of the load based on estimates of a received signal level Ŝi and an interference level based on the PDP, including an estimate of an interference level Îk for a weakest path delay and an estimate of an interference level Îi for a strongest path delay.
A method of generating modified signal-to-noise-ratio (SNR) values in a user equipment in a communication system, comprising the steps of:
- determining, based on a signal from at least one cell in the communication system, a received signal code power (RSCP), a received signal strength indication (RSSI), and a path delay profile (PDP) including a plurality of path delays for the at least one cell;
- estimating a load on the at least one cell;
- and
- generating at least one modified SNR value based on the RSCP, the RSSI, and the load estimates;
- wherein estimating the load on the at least one cell comprises generating the load estimate based on estimates of a received signal level Ŝi and interference level based on the PDP, including an estimate of an interference level Îk for a weakest path delay and an estimate of an interference level Îk for a strongest path delay.
Dependencies are inferred from the claim text.