Cellular network system

• US 7,512,409 B1
• Filed: 01/13/2000
• Issued: 03/31/2009
• Est. Priority Date: 01/13/2000
• Status: Expired due to Fees

• Current Assignee: Zion Hadad Communications, Ltd.
• Original Assignee: Zion Hadad Communications, Ltd.
• Inventors: Hadad, Zion
• Primary Examiner(s): Beamer, Temica M
• Application Number:
  US09/482,030
• Time in Patent Office: 3,365 Days
• Field of Search: 455/447, 455/448, 455/450, 455/451, 455/452.1, 455/454, 455/3.01, 455/503, 455/501, 455/502, 455/63.1, 455/67.11, 455/67.13
• US Class Current: 455/502
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 5/023 Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601

Abstract

A method for providing a personalized bidirectional channel in broadcasting systems. In cellular broadcasting system the method contains the steps of: allocating a first group of subcarriers to broadcast transmission and a second group of subcarriers to personalized channels; reducing interference in the broadcast transmission by using equalizer; and reducing interference in the personalized channels by using controlled allocation of subcarriers in the second group to each subscriber. In OFDM broadcasting system the method contains the steps of: transmitting OFDM transmission from the base-station to the subscriber units; transmitting from the subscriber units to the base-station signals that are orthogonal to signals transmitted from the base-station; and receiving the orthogonal signals at the base-station.

Claims

1. In a SFN cellular broadcast system, means for implementing a bidirectional personalized channel with subscribers, comprising:

A. means for allocating a first group of subcarriers to a broadcast transmission and a second group of subcarriers to personalized channels;

B. Means for reducing interference in the broadcast channel using equalizer means;

C. means for reducing interference in the personalized channel using a controlled allocation of subcarriers in the second group of each subscriber.

2. The SFN cellular broadcast system according to claim 1, wherein said system uses OFDM modulation means.

3. The SFN cellular broadcast system according to claim 1, wherein said controlled allocation of subcarriers in the second group comprises the allocation of separate subcarriers to each of the subscriber units that are close to each other.

4. The SFN cellular broadcast system according to claim 1, wherein said controlled allocation of subcarriers in the second group comprises a measure of overlap in the allocation of subcarriers to each of the subscriber units that are close to each other.

5. The SFN cellular broadcast system according to claim 1, wherein said interference reducing means further include multipath reducing means.

6. In a broadcast SFN system using OFDM transmission from a base-station to subscriber units, means for achieving a bidirectional channel comprising:

transmitting means in the subscriber units for a transmission of signals orthogonal to signals transmitted from the base station, and

receiving means in the base station for receiving the orthogonal signals;

further including;

means in the base station for separate processing of transmit broadcast data and transmit personalized data in the frequency domain, and means for combining the broadcast and personalized data in the frequency domain, prior to conversion to time domain for transmission.

7. In a broadcast SFN system using OFDM transmission from a base-station to subscriber units, means for achieving a bidirectional channel comprising:

transmitting means in the subscriber units for a transmission of signals orthogonal to signals transmitted from the base station, and

receiving means in the base station for receiving the orthogonal signals;

further including;

means in the subscriber unit for converting the received signals to the frequency domain, means for separating broadcast data and personalized data in the frequency domain, and means for separate processing of the broadcast data and the personalized data in the frequency domain.

8. In a broadcast SFN system using OFDM transmission from a base-station to subscriber units, means for achieving a bidirectional channel comprising:

transmitting means in the subscriber units for a transmission of signals orthogonal to signals transmitted from the base station, and

receiving means in the base station for receiving the orthogonal signals;

further including;

means in the base station for transmitting personalized data to each subscriber, comprising means for a transmission of signal orthogonal to broadcast signals and to the signals transmitted from the subscriber units.

9. In a broadcast SFN system using OFDM transmission from a base-station to subscriber units, means for achieving a bidirectional channel comprising:

transmitting means in the subscriber units for a transmission of signals orthogonal to signals transmitted from the base station, and

receiving means in the base station for receiving the orthogonal signals;

wherein the transmitting means further includes a personalized data channel which is inserted after OFDM interleaver stages and in the frequency domain.

10. In a broadcast SFN system using OFDM transmission from a base-station to subscriber units, means for achieving a bidirectional channel comprising:

transmitting means in the subscriber units for a transmission of signals orthogonal to signals transmitted from the base station, and

receiving means in the base station for receiving the orthogonal signals;

wherein the transmitting means further includes means for a dynamic allocation of subcarriers to personalized information.

11. In a broadcast SFN system using OFDM transmission from a base-station to subscriber units, means for achieving a bidirectional channel comprising:

transmitting means in the subscriber units for a transmission of signals orthogonal to signals transmitted from the base station, and

receiving means in the base station for receiving the orthogonal signals;

wherein the transmitting means in the base station further includes means for separate processing of transmit broadcast data and transmit personalized data in the frequency domain.

12. The broadcast SFN system according to claim 11, further including means for combining the processed transmit broadcast data and transmit personalized data, and means for converting the resulting signal to a time domain prior to its transmission.