Method and system for robust, secure, and high-efficiency voice and packet transmission over ad-hoc, mesh, and MIMO communication networks

• US 20080232238A1
• Filed: 07/23/2007
• Published: 09/25/2008
• Est. Priority Date: 06/10/2001
• Status: Active Grant

• Current Assignee: Comcast Cable Communications LLC (Comcast Corporation)
• Original Assignee: Aloft Media, LLC (Oso IP, LLC)
• Inventors: Agee, Brian G.
• Granted Patent: US 8,363,744 B2
• Time in Patent Office: Days
• US Class Current: 370/208
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0443 utilizing "waterfilling" technique
• CPC Class Codes: H04B 7/0456 Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
• CPC Class Codes: H04B 7/0465 taking power constraints at power amplifier or emission constraints, e.g. constant modulus, into account
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04L 27/26 Systems using multi-frequency codes H04L27/32 takes precedence
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 27/2605 Symbol extensions, e.g. Zero Tail, Unique Word [UW]
• CPC Class Codes: H04L 27/2607 Cyclic extensions
• CPC Class Codes: H04L 27/2627 Modulators
• CPC Class Codes: H04L 27/2646 using feedback from receiver for adjusting OFDM transmission parameters, e.g. transmission timing or guard interval length
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 40/04 based on wireless node resources
• CPC Class Codes: H04W 52/241 : taking into account channel quality metrics, e.g. SIR, SNR, CIR, Eb/lo
• CPC Class Codes: H04W 52/265 : taking into account the quality of service QoS
• CPC Class Codes: H04W 52/42 : in systems with time, space, frequency or polarisation diversity
• CPC Class Codes: H04W 72/00 : Local resource management
• CPC Class Codes: H04W 72/04 : Wireless resource allocation
• CPC Class Codes: H04W 72/044 : based on the type of the allocated resource
• CPC Class Codes: H04W 72/0453 : Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/23 : in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 72/542 : using measured or perceived quality
• CPC Class Codes: H04W 88/08 : Access point devices
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

Using at least one MIMO-capable transceiver allows weighting calculations for signals transmitted and received, and enables individual packets to adapt, in a scalable, flexible, and responsive fashion to the real-world dynamics of a continuously varying communications network environment. The method and system of this invention use adaptively-derived diversity means to rapidly and efficiently distinguish the desired signal from noise, network interference, and external interference impinging on the network'"'"'s transceivers and can transmit with lessened overhead. ADC operations and signal transformations continuously update combiner weights to match dynamically-varying environmental and traffic conditions, thereby continuously matching necessitated signal and waveform transformations with environmental and signal effects and sources. Successive iterations of the adaptation algorithm let each node'"'"'s multiport combiner and distribution weights approach the MIMO channel'"'"'s Shannon capacity in high-rate networks, or to minimize power needed to close links at a specified rate in low-rate networks, e.g. Voice-Over-IP networks.

Claims

1. A method and system for robust, secure, and high-efficiency voice and packet transmission over ad-hoc, mesh, and multiple-input, multiple-output (‘

MIMO’

) communication networks, comprising;

communicating through a communications network comprising at least a first MIMO-capable node, said further comprising;

a spatially diverse antennae array of M antennae, where M≧

one,

a transceiver for each antenna in said spatially diverse antennae array,

at least one identifying Node Address when associating in the network that, when that node is Transmitting to at least a second node, becomes an identifying Transmit Node Address (TNA) to that second node and, when that node is receiving from at least a second node, becomes an identifying Receive Node Address (RNA) to the second node;

means for digital signal processing to convert analog radio signals into digital signals and digital signals into analog radio signals,

means for coding and decoding data, symbols, and control information into and from digital signals,

diversity capability means for transmission and reception of said analog radio signals,

and,

means for input and output from and to a non-radio interface for digital signals;

dynamically optimizing a communications network by incorporating environmental adaptation for any Transmit Node Address and Receive Node Address pairing, through the following steps;

at each Transmit Node, to perform each transmit operation, comprising starting with the transmit bits B_TNA(m_frame) to be transmitted over logical subcarrier m_sub and logical frame m_frame and performing the following operations on transmit bits B_TNA(m_frame);

separately encoding each row of transmitted bits B_TNA(m_frame) into QAM symbols;

mapping the QAM symbols to subcarriers to form QAM transmit data Q_TNA(m_sub,m_frame);

embedding the transmit pilot;

mapping the transmit pilot and data to FHT input bins, using;

2. A method as in claim 1, further comprising determining the intended target'"'"'s SINR if not adequately known by deriving it from rate targets based on performance of the codec'"'"'s used in the link.

3. A method as in claim 1, further comprising determining the intended target'"'"'s SINR if not adequately known by deriving it from capacity targets {C_RLA(m_RLA)}.

4. A method as in claim 1, further comprising determining the intended target'"'"'s SINR if not adequately known by deriving it from spectral efficiency targets {c_RLA(m_RLA)}, using:

5. A method as in claim 1, for use when the target SINR'"'"'s are so high that the resultant network is at risk of failing to converge and driving its transmitters into saturation, further comprising:

computing the conducted power into each antenna, using

6. A method as in claim 1, for maximally adapting any portion of the communications network to existing SIR, further comprising:

adaptively computing the receive algorithm for each Node, starting with the multiantenna received and deembedded pilot data P_RNA(m_sub,m_frame) received and OFDM-demodulated over logical subcarrier m_sub and logical frame m_frame, performing the following operations;

computing QRD of P_RNA(m_sub,m_frame);

detecting candidate TNA transmit pilots and spatially-whitened max-SINR adaptation weights;

if spatial signature estimates A_RNA(m_sub) are available, associating detected transmit pilots with receive ports and link addresses;

dropping and adding ports;

assigning max-SINR whitened transmit/receive weights and link statistics;

estimating spatial steering matrices {A_RNA(m_sub,m_frame)};

computing combiner weights {W_RNA(m_sub,m_frame)}; and

,

computing and applying null-steering receive weights and SINR'"'"'s, using;