Method and system for a channel selective repeater with capacity enhancement in a spread-spectrum wireless network

Abstract

The present invention relates to a system and method for extending the coverage area and communication capacity of a spread-spectrum based wireless network through the use of intelligent repeaters. The system comprises a wireless communication network augmented with low cost channel selective repeaters that is capable of repeating only desired signals, thereby suppressing undesirable interference and increasing network capacity. The repeaters can be integrated into an existing wireless network with minimal impact to the existing network layer topology or control structure.

Description

[0001] This application is a continuation in part of, and incorporates by reference in its entirety, U.S. patent application Ser. No. 09 / 953,157 entitled, “METHOD AND SYSTEM FOR A REMOTE DOWNLINK TRANSMITTER FOR INCREASING THE CAPACITY AND DOWNLINK CAPABILITY OF A MULTIPLE ACCESS INTERFERENCE LIMITED SPREAD-SPECTRUM WIRELESS NETWORK,” filed Sep. 17, 2001, and herein referred to as the parent application.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates generally to wireless networks and communication systems. More particularly, the preferred embodiments of the present invention relate to methods and systems for providing intelligent repeaters in spread spectrum communication systems to support selective amplification of communication channels and signals therein. [0004] 2. Description of the Related Art [0005] The field of spread spectrum, wireless communication has been active for over a decade. For instance, the advantages of an exem...

AI Technical Summary

Benefits of technology

[0009] The potentially large computational capabilities of the BS allow sophisticated signal processing algorithms (e.g., floating point calculations, complex demodulation algorithms, and multiple antenna streams) to be employed to increase capacity in the reception of mobile-to-base-station signals (uplink or reverse link) and mitigation of MAI in a spread-spectrum, wireless network. However, the base-station-to-mobile link (downlink or forward link) is limited by the mobile hardware such as the mobile cellular telephone, which is typically quite unsophisticated in comparison to the BS. Thus, the absence of such large computational capabilities at the mobile subscriber introduces a network imbalance that hinders optimizing system performance and balancing system capacity.

Problems solved by technology

However, the base-station-to-mobile link (downlink or forward link) is limited by the mobile hardware such as the mobile cellular telephone, which is typically quite unsophisticated in comparison to the BS.

Thus, the absence of such large computational capabilities at the mobile subscriber introduces a network imbalance that hinders optimizing system performance and balancing system capacity.

However, the network capacity limitation, i.e., the network state of reaching pole capacity, is unique in that increased signal power to overcome the interference of new users does little good.

As transmitted power is increased for all users in an attempt to increase signal power, MAI levels rise nearly a proportionate amount resulting in, still, inadequate SINR values.

In these circumstances, conventional repeaters are ineffective as they indiscriminately amplify all in-band energy, including interference such as the now all-important MAI, particularly on the downlink.

As a result, while most conventional repeaters can be quite effective at increasing both coverage and capacity for wireless networks with sparse distant and shadowed users, they are not so effective in the dense, urban wireless communication networks of today where MAI often dominates over receiver noise for most users.

Thus, conventional urban repeaters only offer increased coverage but not substantially increased capacity of a network cell, which is the basic geographic unit of the cellular structure often employed in wireless networks.

However, by converting channels, these repeaters consume additional network radio resources, must be accounted for in overall network planning, and thereby add complexity to their network integration.

This approach adds great complexity to the hardware and software requirements of such repeaters.

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