Station comprising a rake receiver
View Patent ↗Stations like mobile terminals, bases stations and network nodes comprising rake receivers with fingers require relatively many calculations to be performed for despreading a symbol. By replacing despreading multipliers, integrators and dumpers in the fingers by Hadamard transformers ( 62 ), chips of several symbols with orthogonal channelization codes can be despreaded simultaneously, and the station and the rake receiver have become more efficient. The despreading section ( 60 of the finger ( 34 ) comprises the Hadamard transformer ( 62 ) and a serial-to-parallel converter ( 61 ) comprising downsamplers ( 71 - 73 ). The station is a high-speed downlink packet access station (HSDPA) in a universal mobile telecommunication system (UMTS), with a number of de-channelization codes used being at least ten percent of a despreading factor used. For example, the despreading factor used is equal to sixteen, with the maximum possible number of de-channelization codes used being equal to five, ten or fifteen, depending on the capability class of the station.
1. A station, comprising a rake receiver with a finger, which finger comprises a Hadamard transformer that uses a number of de-channelization codes that is at least ten percent of a despreading factor used.
2. A station as defined in claim 1 , wherein the finger comprises a descrambling section and a despreading section, which despreading sections comprises the Hadamard transformer.
3. A station as defined in claim 2 , wherein the descrambling section comprises a multiplier for multiplying a finger input signal with a complex conjugated scrambling code for descrambling the finger input signal, and wherein the despreading section further comprise a serial-to-parallel converter for serial-to-parallel converting a descrambled signal, which serial-to-parallel converter comprises downsamplers coupled to inputs of the Hadamard transformer and comprises a selector for generating despreaded symbols per channel, which selector is coupled to outputs of the Hadamard transformer.
4. A station as defined in claim 3 , wherein the rake receiver further comprises:
a further finger;
a delaying section for delaying a frequency converted signal and for generating the finger signal destined for the finger and a further finger signal destined for the further finger; and
a synchronization section for receiving the frequency converted signal and for in response controlling the delaying section.
5. A station as defined in claim 1 , wherein the despreading factor used is equal to sixteen, with the maximum possible number of de-channelization codes used being equal to five, ten or fifteen.
6. A rake receiver for use in a station, the rake receiver comprising a finger, which finger comprises a Hadamard transformer, wherein the Hadamard transformer uses a number of de-channelization codes that is at least ten percent of a despreading factor used by the rake receiver.
7. A finger for use in a rake receiver, the finger comprising a descrambling section and a despreading section, said despreading section including a Hadamard transformer that uses a number of de-channelization codes that is at least ten percent of a despreading factor used.
8. A station as defined in claim 1 , further comprising a radio stage having an output coupled to an input of the rake receiver and configured to receive an input radio signal.
9. A rake receiver as defined in claim 6 , wherein the finger comprises a descrambling section and a despreading section, which despreading section comprises the Hadamard transformer.
10. A rake receiver as defined in claim 9 , wherein the descrambling section comprises a multiplier for multiplying a finger input signal with a complex conjugated scrambling code for descrambling the finger input signal, and wherein the despreading section further comprise a serial-to-parallel converter for serial-to-parallel converting a descrambled signal, which serial-to-parallel converter comprises downsamplers coupled to inputs of the Hadamard transformer and comprises a selector for generating despreaded symbols per channel, which selector is coupled to outputs of the Hadamard transformer.
11. A rake receiver as defined in claim 6 , wherein the rake receiver further comprises:
a further finger;
a delaying section for delaying a frequency converted signal and for generating the finger signal destined for the finger and a further finger signal destined for the further finger; and
a synchronization section for receiving the frequency converted signal and for in response controlling the delaying section.
12. A rake receiver as defined in claim 6 , wherein the despreading factor used is equal to sixteen, with the maximum possible number of de-channelization codes used being equal to five, ten or fifteen.
13. A finger as defined in claim 7 , further comprising a descrambling section and a despreading section, which despreading section comprises the Hadamard transformer.
14. A finger as defined in claim 13 , wherein the descrambling section comprises a multiplier for multiplying a finger input signal with a complex conjugated scrambling code for descrambling the finger input signal, and wherein the despreading section further comprise a serial-to-parallel converter for serial-to-parallel converting a descrambled signal, which serial-to-parallel converter comprises downsamplers coupled to inputs of the Hadamard transformer and comprises a selector for generating despreaded symbols per channel, which selector is coupled to outputs of the Hadamard transformer.
15. A finger as defined in claim 7 , wherein the despreading factor used is equal to sixteen, with the maximum possible number of de-channelization codes used being equal to five, ten or fifteen.