Local and wide-area transmissions in a wireless broadcast network

• US 7,660,275 B2
• Filed: 10/18/2004
• Issued: 02/09/2010
• Est. Priority Date: 10/24/2003
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Viswanathan, legal representative, Vijayan, Rajiv, Walker, Gordon Kent, Ling, Fuyun, Mantravadi, Ashok, Subramaniam, Anand, Murali, Ramaswamy
• Primary Examiner(s): Bost; Dwayne
• Assistant Examiner(s): Gonzalez; Amancio
• Application Number:
  US10/968,787
• Publication Number:
  US 20050122928A1
• Time in Patent Office: 1,940 Days
• Field of Search: 370/312, 370/208, 370/478, 370/486, 370/203, 370/344, 370/347, 455/503, 455/502, 455/67.3, 455/67.6, 348/21, 375/260
• US Class Current: 370/312
• CPC Class Codes: H04L 12/189 in combination with wireless systems selective distribution or broadcast in wireless communication networks H04W4/06
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0041 Frequency-non-contiguous
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0048 Allocation of pilot signals, i.e. of signals known to the receiver
• CPC Class Codes: H04W 72/30 Resource management for broadcast services

Abstract

To broadcast different types of transmission having different tiers of coverage in a wireless broadcast network, each base station processes data for a wide-area transmission in accordance with a first mode (or coding and modulation scheme) to generate data symbols for the wide-area transmission and processes data for a local transmission in accordance with a second mode to generate data symbols for the local transmission. The first and second modes are selected based on the desired coverage for wide-area and local transmissions, respectively. The base station also generates pilots and overhead information for local and wide-area transmissions. The data, pilots, and overhead information for local and wide-area transmissions are multiplexed onto their transmission spans, which may be different sets of frequency subbands, different time segments, or different groups of subbands in different time segments. More than two different types of transmission may also be multiplexed and broadcast.

Claims

1. A method of broadcasting data in a wireless broadcast network, comprising:

multiplexing data for a wide-area transmission onto a first transmission span, the wide-area transmission being sent from a plurality of transmitters in the network;

multiplexing data for a local transmission onto a second transmission span, the local transmission being sent from a subset of the plurality of transmitters; and

broadcasting the local and wide-area transmissions via a wireless link using orthogonal frequency division multiplexing (OFDM),

wherein the data for the wide-area transmission and the data for the local transmission are time division multiplexed (TDM) at each base station, wherein the first and second transmission spans are first and second time segments, respectively, of a frame of a predetermined time duration, and the first transmission span includes all frequency subbands usable for data transmission in the first time segment of a frame, and the second transmission span includes all frequency subbands usable for data transmission in the second time segment of the frame, and

wherein the data for the local transmission is multiplexed onto fewer than all usable frequency subbands to reduce interference.

2. The method of claim 1, wherein the data for the local transmission from the subset of the plurality of transmitters is multiplexed onto frequency subbands that are orthogonal to frequency subbands used by at least one other subset of the plurality of transmitters.

3. The method of claim 1, wherein the data for the local transmission is multiplexed onto frequency subbands pseudo-randomly selected from among all usable frequency subbands.

4. A method of broadcasting data in a wireless broadcast network, comprising:

multiplexing data for a wide-area transmission onto a first transmission span, the wide-area transmission being sent from a plurality of transmitters in the network;

multiplexing data for a local transmission onto a second transmission span, the local transmission being sent from a subset of the plurality of transmitters;

broadcasting the local and wide-area transmissions via a wireless link, wherein the data for the wide-area transmission and the data for the local transmission are time division multiplexed (TDM) at each base station, and wherein the first and second transmission spans are first and second time segments, respectively, of a frame of a predetermined time duration;

processing the data for the wide-area transmission in accordance with a first coding and modulation scheme, wherein the processed data for the wide-area transmission is multiplexed onto the first transmission span; and

processing the data for the local transmission in accordance with a second coding and modulation scheme, wherein the processed data for the local transmission is multiplexed onto the second transmission span,

wherein the second coding and modulation scheme has a lower spectral efficiency than the first coding and modulation scheme to extend coverage for the local transmission.

5. A method of broadcasting data in a wireless broadcast network, comprising:

multiplexing data for a wide-area transmission onto a first transmission span, the wide-area transmission being sent from a plurality of transmitters in the network;

multiplexing data for a local transmission onto a second transmission span, the local transmission being sent from a subset of the plurality of transmitters; and

broadcasting the local and wide-area transmissions via a wireless link, wherein the data for the wide-area transmission and the data for the local transmission are time division multiplexed (TDM) at each base station, and wherein the first and second transmission spans are first and second time segments, respectively, of a frame of a predetermined time duration;

processing the data for the wide-area transmission in accordance with a first coding and modulation scheme, wherein the processed data for the wide-area transmission is multiplexed onto the first transmission span; and

processing the data for the local transmission in accordance with a second coding and modulation scheme, wherein the processed data for the local transmission is multiplexed onto the second transmission span, wherein the first coding and modulation scheme has a lower spectral efficiency than the second coding and modulation scheme.

6. A method of broadcasting data in a wireless broadcast network, comprising:

multiplexing data for a wide-area transmission onto a first transmission span, the wide-area transmission being sent from a plurality of transmitters in the network;

multiplexing data for a local transmission onto a second transmission span, the local transmission being sent from a subset of the plurality of transmitters;

broadcasting the local and wide-area transmissions via a wireless link, wherein the data for the wide-area transmission and the data for the local transmission are time division multiplexed (TDM) at each base station, and wherein the first and second transmission spans are first and second time segments, respectively, of a frame of a predetermined time duration; and

adjusting the first and second transmission spans based on time of day.

7. A method of broadcasting data in a wireless broadcast network, comprising:

multiplexing data for a wide-area transmission onto a first transmission span, the wide-area transmission being sent from a plurality of transmitters in the network;

multiplexing data for a local transmission onto a second transmission span, the local transmission being sent from a subset of the plurality of transmitters;

broadcasting the local and wide-area transmissions via a wireless link, wherein the data for the wide-area transmission and the data for the local transmission are time division multiplexed (TDM) at each base station, and wherein the first and second transmission spans are first and second time segments, respectively, of a frame of a predetermined time duration; and

adjusting the first and second transmission spans based on a predetermined schedule.

8. An apparatus in a wireless broadcast network, comprising:

a multiplexer operable to receive and multiplex data for a wide-area transmission onto a first transmission span and to receive and multiplex data for a local transmission onto a second transmission span, the wide-area transmission being sent from a plurality of transmitters in the network, and the local transmission being sent from a subset of the plurality of transmitters;

a transmitter unit operable to broadcast the local and wide-area transmissions via a wireless link, wherein the wireless broadcast network utilizes orthogonal frequency division multiplexing (OFDM), wherein the data for the wide-area transmission and the data for the local transmission are time division multiplexed (TDM) at each base station, wherein the first transmission span includes all frequency subbands usable for data transmission in a first time segment of a frame, and wherein the second transmission span includes all frequency subbands usable for data transmission in a second time segment of the frame; and

a controller operable to select the first and second transmission spans based on an amount of data to broadcast for the wide-area transmission and an amount of data to broadcast for the local transmission.

9. An apparatus in a wireless broadcast network, comprising:

means for multiplexing data for a wide-area transmission onto a first transmission span, the wide-area transmission being sent from a plurality of transmitters in the network;

means for multiplexing data for a local transmission onto a second transmission span, the local transmission being sent from a subset of the plurality of transmitters;

means for broadcasting the multiplexed data for the local and wide-area transmissions via a link, wherein the wireless broadcast network utilizes orthogonal frequency division multiplexing (OFDM), wherein the data for the wide-area transmission and the data for the local transmission are time division multiplexed (TDM) at each base station, wherein the first transmission span includes all frequency subbands usable for data transmission in a first time segment of a frame, and wherein the second transmission span includes all frequency subbands usable for data transmission in a second time segment of the frame; and

means for selecting the first and second transmission spans based on an amount of data to broadcast for the wide-area transmission and an amount of data to broadcast for the local transmission.