Data transmission method and equipment

• US 20040160921A1
• Filed: 10/24/2003
• Published: 08/19/2004
• Est. Priority Date: 04/26/2001
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Tirkkonen, Olav, Kuusela, Markku, Kaipainen, Yrjo
• Granted Patent: US 7,433,339 B2
• Time in Patent Office: Days
• US Class Current: 370/335
• CPC Class Codes: H04B 7/0617 for beam forming
• CPC Class Codes: H04B 7/0619 using feedback from receiving side feedback signaling for adaptive modulation/coding H04L1/0001
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/0691 using subgroups of transmit antennas
• CPC Class Codes: H04W 52/322 Power control of broadcast channels
• CPC Class Codes: H04W 52/325 Power control of control or pilot channels
• CPC Class Codes: H04W 52/42 in systems with time, space, frequency or polarisation diversity

Abstract

Equipment for transmitting a signal, the equipment comprising an antenna array (600-606) for providing three or more radiation antenna patterns. The equipment is arranged to transmit a primary common pilot signal with at most two radiation patterns and a secondary common pilot signal with at least one radiation pattern. The equipment comprises controllers (622a-622d) for adjusting the power ratio between the primary and the secondary common pilot signal and the total power of the primary and the secondary common pilot signals, and controllers (614a-614d) for adjusting the transmit power of the dedicated pilot signal, such that the power levels of the dedicated pilot signals transmitted with the same radiation patterns as the secondary common pilot signal are relatively higher than the power levels of the dedicated pilot signals transmitted with the same radiation patterns as the primary common pilots.

Claims

1. A data transmission method where a signal is transmitted from a transmitter by means of three or more radiation patterns,

characterized by

transmitting a primary common pilot signal by means of at most two radiation patterns and a secondary common pilot signal by means of at least one radiation pattern by adjusting the power ratio between the primary common pilot signal and the secondary common pilot signal and the total power of the primary and the secondary common pilot signal,

transmitting a dedicated pilot signal with at least one user signal with adjustable transmit power, such that the ratio of the power levels of the dedicated pilot signals transmitted with the same radiation patterns as the secondary common pilot signal to the power of the dedicated pilot signals transmitted with the same radiation patterns as the primary common pilot signal is inversely proportional to the power ratio between the corresponding secondary and primary pilot signals, and by

using the dedicated pilot signals transmitted with the same radiation patterns as the secondary common pilot signal for channel estimation measurements in the receiver.

2. A method according to claim 1, characterized in that the dedicated pilot signals to be transmitted with the same radiation patterns as the secondary common pilot signal have relatively higher power levels than the dedicated pilot signals to be transmitted with the same radiation patterns as the primary common pilot signal.

3. A method according to claim 1, characterized in that during reception of a signal transmitted with a radiation pattern including the secondary common pilot signal, channel estimation is carried out on the basis of the dedicated pilot signal and the secondary common pilot signal.

4. A method according to claim 1, characterized in that during reception of a signal comprising a weak secondary common pilot signal and a strong dedicated pilot signal, channel estimation is carried out on the basis of the dedicated pilot signal and the secondary common pilot signal.

5. A method according to claim 1, characterized in that the power ratio of the dedicated pilot signals is obtained by transmitting the dedicated pilot signals to different radiation patterns for different periods of time.

6. A method according to claim 1, characterized by utilizing, in the signal reception, data about channels formed by means of three or more beams, the number of the channels being equal to or greater than the number of the channels used in the actual transmission.

7. A method according to claim 1, characterized by providing the radiation patterns used to transmit the primary common pilot with greater weighting in the signal transmission than the radiation patterns used to transmit the secondary common pilot.

8. A method according to claim 7, characterized by multiplying the signal comprising the primary common pilot with a higher weighting coefficient than the signal comprising the secondary common pilot.

9. A method according to claim 1, characterized by receiving, in an encoder of the transmitter, the channel-coded and interleaved symbols to be transmitted,

subjecting the signal to be transmitted to space-time coding in the encoder of the transmitter to obtain a block-coded signal with MXM orthogonal space-time coding,

subjecting at least one of M data streams to phase shifting in the encoder of the transmitter to obtain a phase-shifted data stream corresponding to a non-phase-shifted data stream,

transmitting each of the M non-phase-shifted data streams and at least one phase-shifted data stream substantially simultaneously via different antennas.

10. A method according to claim 9, characterized in that the symbols to be transmitted include symbols S1 and S2, the space-time block code includes a 2×

2 space-time block code, and the M data streams include symbol stream (S1, S2) transmitted at instants t and t+T and symbol stream (−

S2*, S1*) transmitted at instants t and t+T, where T is a symbol sequence.

11. A method according to claim 1, characterized by receiving the symbols to be transmitted in the encoder of the transmitter, and subjecting the signal to be transmitted to space-time coding in the encoder of the transmitter.

12. A method according to claim 1, characterized by receiving the symbols to be transmitted in the encoder of the transmitter, and subjecting the signal to be transmitted to feedback transmit diversity coding in the encoder of the transmitter, the coding being based at least partly on ancillary information the receiver has transmitted to the transmitter.

13. A method according to claim 1, characterized by receiving the symbols to be transmitted in the encoder of the transmitter, and transmitting at least partly independent data streams to at least three radiation patterns.

14. A data transmission method where a signal is transmitted from a transmitter by means of three or more radiation patterns,

characterized by

transmitting a primary common pilot signal by means of at most two radiation patterns and a secondary common pilot signal by means of at least one radiation pattern by adjusting both the power ratio between the primary and the secondary common pilot signal and the total power of the primary and the secondary common pilot signal,

transmitting a dedicated pilot signal with at least one user signal with adjustable transmit power, such that the ratio of the power levels of the dedicated pilot signals transmitted with the same radiation patterns as the secondary common pilot signal to the power of the dedicated pilot signals transmitted with the same radiation patterns as the primary common pilot signal is inversely proportional to the power ratio between the corresponding secondary and primary pilot signals, and by

carrying out general measurements related to wireless communication, excluding channel estimation of the radiation patterns corresponding to the non-primary common pilot channels, by means of the primary common pilot channels or the primary common pilot channels and the corresponding dedicated channels.

15. A method according to claim 14, characterized in that the general measurements include SIR, handover, free mode cell selection and synchronization measurements.

16. Equipment for transmitting a signal, the equipment comprising an antenna array (600-606) providing three or more radiation antenna patterns, characterized in that the equipment comprises

means (620a, 624a, 618a, 600, 620b, 624b, 618b, 602) for transmitting a primary common pilot signal with at most two radiation patterns,

means (620c, 624c, 618c, 604, 620d, 624d, 618d, 606) for transmitting a secondary common pilot signal with at least one radiation pattern,

means (622a-622d) for adjusting both the power ratio between the primary and the secondary common pilot signal and the total power of the common pilot signals, means (614a-614d) for adjusting the transmit power of the dedicated pilot signal transmitted with each user signal, such that the ratio of the power levels of the dedicated pilot signals transmitted with the same radiation patterns as the secondary common pilot signal to the power of the dedicated pilot signals transmitted with the same radiation patterns as the primary common pilot signal is inversely proportional to the power ratio between the corresponding secondary and primary pilot signals.

17. Equipment according to claim 16, characterized in that the equipment comprises means (614a-614d) for adjusting the transmit power of the dedicated pilot signal transmitted with each user signal, such that the dedicated pilot signals to be transmitted with the same radiation patterns as the secondary common pilot signal have relatively higher power levels than the dedicated pilot signals to be transmitted with the same radiation patterns as the primary common pilot signal.

18. Equipment according to claim 16, characterized in that the equipment is arranged to utilize, in the signal reception, data about channels formed by means of three or more beams, the number of the channels being equal to or greater than the number of the channels used in the actual transmission.

19. Equipment according to claim 16, characterized in that the equipment comprises means (626a-626d) for providing the radiation patterns used to transmit the primary common pilot signal with greater weighting than the radiation patterns used to transmit the secondary common pilot signal.

20. Equipment according to claim 16, characterized in that the equipment is a base station transceiver or a terminal equipment in a cellular radio system.

21. Equipment according to claim 16, characterized in that the transmitter comprises means (702) for subjecting the signal to be transmitted to space-time coding to obtain a block-coded signal with MXM orthogonal space-time coding,

means (630, 632) for shifting the phase of each of M data streams to provide a phase-shifted data stream corresponding to a non-phase-shifted data stream, and

means (618a-618d) for transmitting each non-phase-shifted data stream and phase-shifted data stream substantially simultaneously via different antennas (600-606).

22. Equipment for receiving a signal comprising a primary and a secondary common pilot signal and a dedicated pilot signal, the equipment comprising one or more antennas (522) for receiving a signal from a transmitter, means (526) for determining the power level of the received common pilot signals and the power level of the received dedicated pilot signal, and means (526) for subjecting the received signal to channel estimation, characterized in that the equipment comprises means (538) for guiding the channel estimation means to perform estimation on the dedicated pilot signal and the secondary pilot signal during reception of a signal including a weak secondary common pilot signal and a strong dedicated pilot signal.

23. Equipment according to claim 22, characterized in that the equipment comprises means (526) for determining the power ratio between the common pilot signal and the dedicated pilot signal.

24. Equipment according to claim 22, characterized in that the equipment is a terminal equipment or a base station transceiver in a cellular radio system.