Increased data communication capacity of a high rate wireless network

• US 6,922,570 B2
• Filed: 05/04/2001
• Issued: 07/26/2005
• Est. Priority Date: 05/05/2000
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Agere Systems Incorporated (Broadcom, Inc.)
• Inventors: Van Nee, D. J. Richard, Awater, Greet Arnout
• Primary Examiner(s): Beamer, Temica M.
• Application Number:
  US09/849,089
• Publication Number:
  US 20020072392A1
• Time in Patent Office: 1,544 Days
• Field of Search: 375/219, 375/220, 370/208, 370/210, 370/329, 370/277, 370/330, 370/281, 455/561, 455/562.1, 455/103
• US Class Current: 455/561
• CPC Class Codes: H04B 7/0615 of weighted versions of same signal
• CPC Class Codes: H04B 7/0854 using error minimizing algorithms, e.g. minimum mean squared error [MMSE], "cross-correlation" or matrix inversion

Abstract

The invention relates to a wireless radiofrequency data communication system comprising:

• • a base-station comprising multiple first sets and a signal processing-unit, wherein each first set comprises a transmitter- and receiver-unit provided with a transmitter and a receiver and at least one antenna which is connected to the transmitter- and receiver-unit, wherein the signal processing-unit is connected with each of the first sets for processing signals received by the first sets and processing signals to be transmitted by the first sets, and
  • multiple second sets, wherein each second set comprises a transmitter- and receiver-unit provided with a transmitter and a receiver and at least one antenna which is connected to the transmitter- and receiver-unit.

Claims

1. Wireless radiofrequency data system comprising:

a base-station comprising N first sets and a signal processing-unit connected with each of the N first sets for processing signals received and to be transmitted by the N first sets, and

M seconds sets with N greater than M, wherein each first set and each second set comprises a transmitter- and receiver-unit having at least one antenna and provided with a transmitter and a receiver that operate on essentially the same radiofrequency or radiofrequency-band, wherein the signal processing-unit is provided with an inputport for inputting M signals Q to be received by the respective M second sets and comprises information about transfer-functions H of radiofrequency signals from each of the antennas of the N first sets to each of the antennas of the M second sets and/or vice versa, and wherein the signal processing-unit processes the signals received and to be transmitted by the N first sets on the basis of said transfer functions H such that for each second set of a plurality of the M second sets an individual communication channel is formed with the base-station wherein these communication channels are generated simultaneously and separately from each other, wherein the processing unit is arranged to process the M signals Q in combination on the basis of information of the transfer-functions H to establish M of said simultaneous communication channels by processing on the basis of the information about the transfer-functions H, the M signals Q to obtain the N transmit-signals R, to be transmitted by the first sets to the second sets, according to

R=P_DQ, 

 

(A)

resulting in that the M signals Q are received separately by the respective second sets if the second sets each receive the N transmit-signals, where P_D=[H*(H*H)<sup>−

1</sup>]^T is the pseudoinverse of H^T and where H* is the complex conjugated and transposed of H, wherein H is a complex [N*M] matrix containing transfer functions h_ij(i=1, . . . , N;

j=, . . . , M), wherein h_ij is the transfer function for transmission from the i^th second set of the M second sets to the i^th first set of the N first sets, and where Q is a complex M dimensional vector [Q₁, Q₂, . . . Q_j, . . . , Q_m] wherein O_j is the signal to be transmitted to the j^th second set of the M second sets and where R=[R₁, R₂, . . . R_j, . . . R_N]^T wherein R_i is the transmit-signal to be transmitted by the i^th first set of the N first sets.

2. Wireless radiofrequency data communication system according to claim 1, characterised in that, the communication channels are duplex communication channels.

3. Wireless radio-frequency data communication system comprising in use:

k1 multiple first groups, wherein each first group comprises a transmitter-unit and at least one antenna which is connected to the transmitter-unit for transmitting a signal; and

k2 multiple second groups, which each second group comprises a receiver-unit and at least one antenna which is connected to the receiver-unit,

characterised in that, the wireless radiofrequency data communication system further comprises a signal processing-unit which is k₁>

k₂ connected to each of, the first groups and which is, if k₁<

k₂, connected to each of, the second groups, wherein the signal processing-unit comprises information about the transfer-functions of radiofrequency signals from each of the first groups to each of the second groups, and/or vice versa, and wherein, each of the transmitter-units, of the first groups operates on essentially the same radiofrequency or radio frequency band, and wherein, in use, if k₁>

k₂, the signal processing-unit processes k₂ data-signals to be transmitted to the k₂ second groups for obtaining k₁ signals which are supplied to the respective first groups to be transmitted, where the k₂ data signals are processed on the basis of said transfer functions in such a manner that the respective second groups will receive separately the respective k₂ data-signals, thereby establishing k₂ simultaneous communication channels, and wherein, in use, if k₁<

k₂, the signal processing-unit processes k₂ signals, which are received by the respective second groups on the basis of said transfer functions in such way that an estimation is made of the k₁ signals transmitted by the first groups, thereby establishing k₁ simultaneous communication channels.

4. Wireless radiofrequency data communication system according to claim 3, characterised in that each first group comprises a serial-to.parallel-to-serial unit, which unit, in use, splits the data signal in a multiple of signals, and means for modulating these signals on different frequencies according to the Inverse Fast Fourier Transformation, and wherein each second group comprises a unit for executing a Fast Fourier Transformation on the signal received by said second group and means for combining the transformed signals in order to recover said data-signal.

5. Wireless radiofrequency data system comprising:

a base-station comprising N first sets and a signal processing-unit connected with each of the N first sets for processing signals received and to be transmitted by the N first sets, and

M seconds sets with N greater than M, wherein each first set and each second set comprises a transmitter- and receiver-unit having at least one antenna and provided with a transmitter and a receiver that operate on essentially the same radiofrequency of radiofrequency-band and, in use, each of the M second sets transmits a signal so that M signals are transmitted to be received in combination by the N first sets, wherein the signal processing-unit comprises information about transfer-functions H of radiofrequency signals from each of the antennas of the first sets to each of the antennas of the second sets and/or vice versa, and processes the signals received and to be transmitted by the N first sets on the basis of said transfer functions H, such that for each second set of a plurality of the M second sets an individual communication channel is formed with the base-station wherein these communication channels are generated simultaneously and separately from each other, wherein the signal processing-unit is arranged to recover the M signals transmitted by the M second sets separately from each other, thereby obtaining M of said simultaneous communication channels, by processing on the basis of the information about the transfer-functions H, the signals r which are received by the first sets, to calculate an estimation x_est of the M signals x^c which were transmitted by the M second sets, according to the mathematical expression

x_est=P_Ur, 

 

(B)

where P_U=[(H*H)<sup>−

1</sup> H*] is the pseudo-inverse for H and where H* is the complex conjugated and transposed of H, wherein H is a complex [N*M] matrix containing transfer functions h_ij(i=1, . . . , N;

i=1, . . . , M), wherein h_ij is the transfer function for transmission from the i^th second set of the M second sets to the i^th first set of the N first sets, r is a complex N dimensional vector [r₁, . . . , r_i, . . . , r_N]^T with r_i the signal received by the i^th first set of the N first sets, x_est is a complex M dimensional vector [x_est_j, . . . , x_est_j, . . . , x_est_M]^T where x_est_j is an estimation of x^c_j, and wherein x^c is a complex M-dimensional vector [x^c₁, . . . , x^c_j, . . . , x^c_M]^T, with x^c_j being the signal transmitted by the j^th second set of the M second sets.

6. Wireless radiofrequency data communication system according to claim 5, characterised in that each second set comprises a serial-to-parallel/parallel-to-serial unit, which unit, in use, splits the data signal of said second set in a multiple of signals, an means for modulating these signals on different frequencies according to the Inverse Fast Fourier Transformation, and wherein each first set comprises a unit for executing a Fast Fourier Transformation on the signals received by said first set and means for combining the transformed signals in order to recover said data-signal.