초록 ▼

Method and device for interference cancellation. A radio access unit comprises a plurality of directionally separated antenna elements (41k, K=1, 2, . . . , L) for receiving signals transmitted by a plurality of remote units. From signals received by each of the antenna elements (41k) first weighing

Method and device for interference cancellation. A radio access unit comprises a plurality of directionally separated antenna elements (41k, K=1, 2, . . . , L) for receiving signals transmitted by a plurality of remote units. From signals received by each of the antenna elements (41k) first weighing factors (g(1)k) are determined (49), for optimally selecting signal of a first remote unit (521). A first radio signal (s1) of the first communication unit (521) is provided by weighing (44) the received signals using the first weighing factors (g(1)k). For a further radio communication unit (52i) further weighing factors (g(i)k) are determined. A corrected further radio signal (s′i) is provided each time by subtracting (46) from the further radio signal (si), previously obtained corrected radio signal (S′i-1, S′i-1, . . . ) weighed by the further weighing factors (g(i)k), till a stop criterium has been satisfied.

대표청구항 ▼

The invention claimed is: 1. A method of interference cancellation in radio communication signals received by a radio access unit of a radio communication system, said radio access unit comprising receiver means and antenna means, said antenna means having a plurality of directionally separated ant

The invention claimed is: 1. A method of interference cancellation in radio communication signals received by a radio access unit of a radio communication system, said radio access unit comprising receiver means and antenna means, said antenna means having a plurality of directionally separated antenna elements for adaptively receiving radio communication signals transmitted by a plurality of remote mobile radio communication units, said method comprising the steps of: a) obtaining radio signals received by each of said antenna elements; b) determining first weighing factors for optimally selecting radio signals of a first mobile radio communication unit among said radio signals obtained in step a); c) weighing said radio signals obtained in step a) by said first weighing factors providing a first radio signal of said first radio communication unit; d) determining second weighing factors for optimally selecting radio signals of a second mobile radio communication unit among said radio signals obtained in step a); e) weighing said radio signals obtained in step a) by said second weighing factors providing a second radio signal of said second radio communication unit; f) subtracting from said second radio signal provided in step e) said first radio signal provided in step c) weighed by said second weighing factors, providing a corrected second radio signal, and g) repeating steps d) to f) for a further mobile radio communication unit by determining further weighing factors, providing a further radio signal of said further radio communication unit and providing a corrected further radio signal by each time subtracting from said further radio signal said previously obtained corrected radio signals weighed by said further weighing factors by reconstructing the first and second radio signals and accumulating the reconstructed first and second radio signals which reduces interference to the further radio signal from the first and second radio signals, till a stop criterion has been satisfied. 2. The method according to claim 1, wherein said weighing factors are obtained by forming conceptual antenna patterns with said plurality of directionally separated antenna elements. 3. The method according to claim 2, wherein said weighing factors are selected for optimally selecting radio signals of a respective radio communication unit and for optimally suppressing radio signals corresponding to any other radio communication unit. 4. The method according to claim 3, wherein said criterion includes stopping of step g) once a corrected radio signal has been provided corresponding to a radio communication unit of interest. 5. The method according to claim 1, wherein said radio signals obtained in step a) are ordered from strongest to weakest according to receive signal strength, and wherein said first, second and further radio communication units are selected in descending order of receive signal strength. 6. The method according to claim 1, wherein said first, second and further corrected radio signals are demodulated into first, second and further demodulated signals, respectively, and stored in storage means, and wherein for providing said corrected radio signals said demodulated signals are reconstructed into corresponding radio signals. 7. The method according to claim 1, wherein said stop criterion includes repetition of step g) for said first, second and further radio communication units till said interference cancellation in said first, second and further radio signals between successive repetitions of step g) drops below a set value. 8. The method according to claim 1, wherein said stop criterion includes repetition of step g) for said first, second and further radio communication units during a set time period. 9. The method according to claim 1, wherein said radio signals obtained in step a) are digitized and said steps b) to d) are performed in the digital domain by digital signal processing means. 10. The method according to claim 1, wherein said demodulation and reconstruction are performed in the digital domain by digital signal processing means. 11. A signal processing device for interference cancellation in radio communication signals received by a radio access unit of a radio communication system, said radio access unit comprising receiver means and antenna means, said antenna means having a plurality of directionally separated antenna elements for adaptively receiving radio communication signals transmitted by a plurality of remote mobile radio communication units, said device comprising: means for storing radio signals received by each of said antenna elements; means for determining respective weighing factors for optimally selecting radio signals of a respective mobile radio communication unit among said stored radio signals; means for weighing said stored radio signals by said respective weighing factors for providing a respective radio signal of said respective radio communication unit; and means for subtracting from said respective radio signal previously determined corrected radio signals of radio communication units weighed by said respective weighing factors by reconstructing radio signals of any other radio communication units and accumulating the reconstructed radio signals of any other radio communication units, for providing a corrected respective radio signal which reduces interference to the respective radio signal from the radio signals of any other radio communication units. 12. The device according to claim 11, wherein said means for determining respective weighing factors are arranged for forming conceptual antenna patterns with said plurality of directionally separated antenna elements. 13. The device according to claim 11, wherein said means for determining said respective weighing factors are arranged for optimally selecting radio signals of a respective radio communication unit and for optimally suppressing radio signals corresponding to any other radio communication unit. 14. The device according to claim 11, further comprising means for measuring signal strength of said stored radio signals, and means for ordering stored radio signals from strongest to weakest according to receive signal strength, and control means for processing said ordered radio signals in descending order of receive signal strength. 15. The device according to claim 11, comprising means for demodulating said respective corrected radio signals, further means for storing said demodulated signals, and means for reconstructing said demodulated signals providing corrected radio signals for weighing by said weighing means. 16. The device according to claim 15, wherein said demodulation means and reconstruction means are implemented in the digital domain by digital signal processing means. 17. The device according to claim 11, comprising means arranged for stopping signal processing in accordance with a stopping criterion including any of stopping said signal processing: once a corrected radio signal corresponding to a radio communication unit of interest has been provided until said interference cancellation, between successive repetitions of providing a corrected respective radio signal, said signal processing drops below a set value, or after a set time period lapses. 18. The device according to claim 11, comprising analog to digital conversion means for digitizing said stored radio signals, wherein said processing means are digital signal processing means.