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AssigneeThe DIRECTV Group, Inc.
InventorsDale A. Branlund, Matthew C. Bromberg
Estimating the term…
A new frame structure applicable to the IEEE 802.16 OFDMA wireless waveform is described, for the purposes of increasing base station capacity, increasing subscriber link rates and extending base station range. The frame structure provides the necessary constructs so that advance signal processing technologies such as Stacked Carrier Spread Spectrum and adaptive antenna technology may be used in combination with these constructs in order to realize these gains. These concepts are equally applicable in other advanced wireless waveforms based on OFDM or OFDMA such as LTE or UMB.
An adaptive antenna system (AAS) comprising a plurality of antennae for communicating between a base station and a subscriber station, wherein the AAS employs a direct signaling structure configured to use a downlink subframe and an uplink subframe, wherein the base station generates the downlink subframe and the subscriber station generates the uplink subframe, the downlink subframe comprises:
A method of communicating between a base station and a subscriber system that perform stacked carrier spread spectrum and stacked carrier spread spectrum (SCSS) adaptive array processing using an adaptive antenna system (AAS) Directed Signaling (DS) frame, the method comprising:
A method for communicating between base and subscriber stations using an adaptive antenna system (AAS) direct signaling structure, the method comprising:
Dependencies are inferred from the claim text.
From the US filing history. Foreign family members aren’t listed.
Signal structure: symbol extensions, e.g. Zero Tail, Unique Word [UW]
Using simultaneous transmission: using different spreading codes between antennas
At least one of which is mobile: using frequency division multiple access [FDMA]
Arrangements for allocating sub-channels of the transmission path: allocation of payload; Allocation of data channels, e.g. PDSCH or PUSCH
About 3 years 8 months of term left · ends 29 Jun 2030 (estimated)
The following disclosure submitted herewith as a U.S. Patent application. Knowledge of the references cited herein, as well as the current proposal for 802.16, is assumed. While this document proposes a new AAS frame/zone to the 802.16 orthogonal frequency-division multiple access (OFDMA) frame structure in order to support high capacity base stations and high capacity mobile relay base stations, it contains teachings that are broader in scope than that specific purpose.
The term AAS (adaptive antenna system) refers to an orthogonal frequency-division multiplexing (OFDM) or OFMDA system adaptively exploiting more than one antenna to improve the coverage and the system capacity. Multi-user AAS refers to the ability to support multiple user links simultaneously on the same sub-channel in the same timeslot through the use of AAS techniques coupled with active interference cancellation. Multi-user AAS is also referred to as “multi-beam adaptive beamforming and null-steering”. Stacked carrier spread spectrum (SCSS) is a new form of spread spectrum first described in U.S. Pat. No. 6,128,276 that, in combination with code nulling, can communicate with multiple users by adaptive coding redundant data onto separate OFDM subcarriers. Extensions of SCSS include the seamless integration of spatially disperse copies of the same data received on the same subcarriers. When used in this way, the processing is called SCSS adaptive array processing. When code nulling is applied in SCSS, then multiple users can be optimally isolation from each other in “code space” or in “generalized code space” by adding spatial samples to the solution.
The present invention provides, in one aspect, a new frame structure applicable to the IEEE 802.16 OFDMA wireless waveform, for the purposes of increasing base station capacity, increasing subscriber link rates and extending base station range. The frame structure provides the necessary constructs so that advance signal processing technologies such as Stacked Carrier Spread Spectrum and adaptive antenna technology may be used in combination with these constructs in order to realize these gains.
FIG. 1 illustrates the composition the AAS frame.
FIG. 2 illustrates the detailed frame structure for one-half of the RF (5 MHz in this case) channel.
FIG. 3 illustrates partition construction detail.
Multi-user technology extends cell coverage by improving the system link budget and lowering the interference floor. Link budget gain is realized through the combining of signals received and/or transmitted from multiple antenna elements and/or multiple subcarriers, as well as by increasing the diversity provided by a multi-element antenna array and/or multiple copies of the signal. At the same time, multi-user SCSS adaptive arrays increases base station capacity by enabling the use of higher order modulation and reuse of spectral resources within the same cell. Finally, we define an AAS frame and AAS zone consistent with the definition in the IEEE 802.16 standard. These definitions describe frames or zones where adaptive array processing is enabled. AAS methods include conventional adaptive array processing or SCSS adaptive array processing.
This document thus describes modifications to the 802.16 OFDMA AAS zone structure, adds new AAS training sequences and modifies associated MAP IEs in order to achieve higher spectral efficiency of MMR-base stations in realistic propagation environments and enable the use of multi-user AAS on the MMR-BS-RS link. Moreover, modifications are described to increase capacity on the bandwidth request signaling channel so that bandwidth requests and grant allocations scale linearly with higher capacity.
Various aspects of the present invention are described, in a manner that is intended to facilitate understanding of the various different inventions herein. Aspects of these various inventions can also be combined, as will be apparent.