Prior art — US Patent 6604216

Prior Art Analysis for US Patent 6,604,216

As of May 12, 2026, the following analysis details the most relevant prior art cited during the prosecution of US Patent 6,604,216. The analysis is based on the references listed in the patent's file wrapper and focuses on the potential for anticipation under 35 U.S.C. § 102. For a claim to be anticipated, every element and limitation must be found in a single prior art reference, arranged as in the claim.

The core inventive concept of patent 6,604,216 is a flexible method for implementing Incremental Redundancy (IR) Hybrid ARQ (HARQ). This method involves encoding a data block into a "mother code word," reordering this codeword according to an "ordering vector," and then transmitting variable-length "subsequences" from this single reordered codeword. The length of each subsequence is specifically chosen to fill the bandwidth of an available, and potentially variable, gross rate channel.

1. US Patent 5,657,325

Full Citation: US Patent 5,657,325 A, "Transmitter and method for transmitting information packets with incremental redundancy." Assigned to Lucent Technologies Inc.
Publication Date: August 12, 1997 (Filed March 31, 1995).
Description: This patent describes a system for transmitting information packets using incremental redundancy. An information block is encoded to generate a codeword, which is then partitioned into multiple sub-blocks of redundancy bits. A first sub-block is transmitted, and if the receiver fails to decode the information, it requests additional, different sub-blocks. This process continues until successful decoding occurs. This is a foundational patent for Type II/III Hybrid ARQ schemes.
Anticipation Analysis: While US 5,657,325 teaches the fundamental concept of incremental redundancy, it does not appear to anticipate the key claims of patent 6,604,216. The '325 patent describes partitioning a codeword into distinct sub-blocks, which are often of a fixed size suitable for fixed-rate channels. It does not disclose the specific mechanism of creating a single reordered mother code word based on an ordering vector and then selecting subsequences of arbitrary length from it to match variable available gross rate channels. This flexibility to create a subsequence of any desired length is a central element of the '216 patent's claims (e.g., Claim 1: "each of the at least one modulated subsequence having a desired number of bits taken from the reordered mother code word to fill the available bandwidth"). The '325 patent lacks this specific teaching of reordering and flexible subsequence selection.

2. US Patent 5,940,439

Full Citation: US Patent 5,940,439 A, "Method and apparatus for adaptive rate communication system." Assigned to Motorola Inc.
Publication Date: August 17, 1999 (Filed February 26, 1997).
Description: This patent discloses an adaptive communication system that adjusts its data transmission rate based on channel quality. It achieves different code rates by applying various puncturing patterns to a low-rate mother code. The system selects a puncturing pattern that corresponds to a desired code rate suitable for the current channel conditions. This is a form of Link Adaptation (LA).
Anticipation Analysis: US 5,940,439 is highly relevant but does not anticipate the claims of 6,604,216. The '439 patent describes a system with a discrete set of puncturing patterns, each corresponding to a specific code rate. This is the exact prior art approach that patent 6,604,216 aims to improve upon. The '216 patent consolidates multiple puncturing concepts into a single ordering vector to create one continuous reordered mother code word. From this single reordered word, the transmitter can select a subsequence of any length, not just lengths corresponding to a predefined set of puncturing patterns. This allows it to dynamically and flexibly match the available bandwidth of any gross rate channel. The '439 patent does not teach this method of reordering and then selecting a variable-length subsequence from a single, pre-ordered bitstream.

3. DE 19630343 A1

Full Citation: DE 19630343 A1, "Method, device and packet transmission system using error correction of data packets." Assigned to Telefonaktiebolaget LM Ericsson.
Publication Date: February 5, 1998 (Filed July 26, 1996).
Description: This German patent application, from the same original assignee as the '216 patent, describes a method for transmitting data packets with error correction. It involves encoding data and transmitting redundancy information in stages. It focuses on retransmitting packets in a mobile communication system, using different versions of the packet (with different redundancy information) for retransmissions to improve the probability of successful decoding.
Anticipation Analysis: This reference describes a form of HARQ. However, like the other references, it does not appear to disclose the specific inventive step of patent 6,604,216. There is no evidence that it teaches the creation of a single reordered mother code word via an ordering vector from which variable-length subsequences can be drawn to precisely match the capacity of variable-rate channels. As it originates from the same company, it likely represents foundational work in the area, but it lacks the specific combination of claim elements that define the novelty of the '216 patent.

4. EP 0104703 A1

Full Citation: EP 0104703 A1, "Electrolytic capacitor." Assigned to Koninklijke Philips Electronics N.V.
Publication Date: April 4, 1984 (Filed September 24, 1982).
Description: This patent relates to the structure and manufacturing of electrolytic capacitors.
Anticipation Analysis: This reference is not relevant to the subject matter of US patent 6,604,216. Its citation appears to be an error, as its technical field is entirely unrelated to telecommunications, error correction codes, or data transmission protocols. It cannot anticipate any claim of the '216 patent.