Feedback method for cooperating relay transmission

Abstract

The invention discloses a feedback method for cooperating relay transmission, which comprises the steps that: (1) an identical current cluster node list is established and maintained in upstream cluster relay nodes and current cluster relay nodes; (2) an upstream cluster performs hop-by-hop transmission on the current cluster, and the current cluster relay nodes perform decoding and inspection onsignals; (3) a physical layer feedback space has wireless resources with certain duration and bandwidth and is divided into a plurality of physical layer feedback bits, and a modulation mode selectedby each feedback bit is expressed as a molecular channel, a frequency molecular channel, a code molecular channel or a combination mode thereof; and (4) through pure distributed feedback or semi-centralized feedback based on the physical layer feedback space, both the upstream cluster relay nodes and the current cluster relay nodes acquire feedback results of all current cluster relay nodes, and judge that the decoding of the current cluster relay nodes fails completely or partially or succeeds completely, and the hop-by-hop transmission, sharing retransmission in the clusters or the next hop-by-hop transmission is started. The feedback method has the advantages of little expenditure and small and fixed time delay.

Description

technical field [0001] The present invention relates to the technical field of communication, in particular, to a feedback method for cooperative relay transmission. Background technique [0002] With the development of wireless communication services and the extensive development and application of Internet technology and services, the diversification and multimediaization of communication services, especially wireless / mobile communication services, the demand for transmission bandwidth of wireless / mobile communication systems is increasing, and The improvement of transmission bandwidth by many modulation techniques and coding techniques has approached the Shannon limit. Multiple Input Multiple Output (MIMO, Multiple In and Multiple Out) technology emerged as the times require, but MIMO technology requires multiple antennas to be arranged on communication nodes, and the distance between antennas is at least greater than a quarter of the working wavelength, so it is mainly u...

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Problems solved by technology

[0015] Since the node to be selected may give feedback on any number of feedback time slots, its feedback message must contain its unique ID to determine the feedback node. If the MAC address is used as the ID, the message must contain at least 48 bits, and the MAC Messages have other overheads, so this type of feedback mechanism based on the MAC mechanism has a large overhead and a large delay; in addition, if the probability q is selected too large, at least two or more nodes will send feedback simultaneously on the same feedback time slot The probability of conflict caused by the message is also increased; for a fixed q, the larger the number of active nodes is, the greater the probability of conflict is; and if the choice of q is too small, although the probability of conflict is reduced, the number of nodes sending feedback messages is also reduced. No node even sends a feedback message, theoretically when q opt =1 / N, the probability of non-conflict is at most p max =(1-1 / N) N-1 , but this requires predicting the number of nodes N before feedback

Although in the prior art, there is a simple "Hello" message mechanism and called "1-bit" mechanism, but it is not the case, because the MAC message is much more than 1-bit, thus introducing at least the delay of the minimum MAC packet , and the delay introduced is proportional to the number N of users who need to participate in the cooperative relay in the cluster. If the exponential backoff of the competition mechanism is considered, the delay will be larger and more difficult to predict, so it is time-consuming and wastes precious resources. Wireless resources, extremely uneconomical

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