# US 10,320,517 B2 · Switched transmit antennas with no feedback for multipath reduction > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,320,517 B2 - Document ID: US10320517B2 - Status: Granted - Kind: B2 - Application number: 15/614,138 - Filed: 2017-06-05 - Published: 2018-12-06 - Granted: 2019-06-11 - Earliest claimed: 2017-06-05 - Assignees: J3 Technology LLC - Applicants: James A Xanthos; John S Cooper, Jr. - Inventors: James A Xanthos; John S Cooper, Jr. - Web page: https://patentgrep.com/patent/US10320517B2 ## CPC - H04K 3/62: {by exposing communication, processing or storing systems to electromagnetic wave radiation, e.g. causing disturbance, disruption or damage of electronic circuits, or causing external injection of faults in the information} - H04B 7/0604: {with predefined switching scheme} - H04B 7/0606: {Random or pseudo-random switching scheme} - H04K 3/28: {with jamming and anti-jamming mechanisms both included in a same device or system, e.g. wherein anti-jamming includes prevention of undesired self-jamming resulting from jamming} - H04K 3/86: {related to preventing deceptive jamming or unauthorized interrogation or access, e.g. WLAN access or RFID reading (record carriers with integrated circuit chips including means for preventing undesired reading or writing from or to record carriers by hindering electromagnetic reading or writing G06K19/07318; arrangements for sensing record carriers including arrangements for protecting the interrogation against piracy attacks G06K7/10257)} - H04K 2203/16: for telephony - H04K 2203/32: including a particular configuration of antennas - H04K: SECRET COMMUNICATION; JAMMING OF COMMUNICATION - H04B: TRANSMISSION ## Abstract A communication system is provided comprising a transmitter coupled to a switch, which is further coupled to at least two antennas for switching the transmit signal to one of the antennas, with no feedback. The communication system further comprises at least one receiver for receiving the transmitted signal. The communication system in the present invention is able to help mitigate the effects of multipath. Previous attempts to mitigate the effects of multipath suffer from various problems: increased complexity needed to measure channel parameters and a feedback loop to switch the transmit antenna based on the parameters. The system is particularly useful when deployed in a MAS system or a jamming system. ## Claims ### Claim 1 A communication system for reducing multipath comprising: a transmitter; a switch coupled to the transmitter; at least two antennas, coupled to the switch, for switching a transmit signal to one of the antennas, wherein the transmit signal is received by at least one receiver through a receive antenna; and wherein the switch switches the transmit signal with no explicit and no implicit feedback associated with the at least one receiver. ### Claim 2 (depends on 1) The communication system according to claim 1, wherein the switch is switched periodically based on a fixed time period. ### Claim 3 (depends on 1) The communication system according to claim 1, wherein the switch is switched periodically based on a random time period. ### Claim 4 (depends on 2) The communication system according to claim 2, wherein the fixed time period is equal for each antenna. ### Claim 5 (depends on 2) The communication system according to claim 2, wherein the fixed time period is not equal for each antenna. ### Claim 6 (depends on 1) The communication system according to claim 1, wherein an external transmit signal is transmitted by an external transmitter. ### Claim 7 (depends on 6) The communication system according to claim 6, wherein the transmit signal dominates the external transmit signal. ### Claim 8 (depends on 6) The communication system according to claim 6, wherein the transmitter is a jammer. ### Claim 9 (depends on 6) The communication system according to claim 6, wherein the transmitter is a part of a DAS system. ### Claim 10 A communication system for reducing multipath comprising: a first transmitter; a switch, coupled to the first transmitter; at least two antennas, coupled to the switch, wherein the switch switches a first transmit signal to one of the antennas; a first receiver, associated with the first transmitter; and a first receive antenna coupled to the first receiver for receiving an ambient signal environment; wherein the first transmit signal is received by at least one secondary receiver, through a secondary receive antenna, and the secondary receiver is associated with at least one respective secondary transmitter, coupled to a secondary transmit antenna; and wherein the switch switches the first transmit signal with no explicit and no implicit feedback associated with the at least one secondary receiver. ### Claim 11 (depends on 10) The communication system according to claim 10, wherein the switch is switched periodically based on a fixed time period. ### Claim 12 (depends on 10) The communication system according to claim 10, wherein the switch is switched periodically based on a random time period. ### Claim 13 (depends on 11) The communication system according to claim 11, wherein the fixed time period is equal for each antenna. ### Claim 14 (depends on 11) The communication system according to claim 11, wherein the fixed time period is not equal for each antenna. ### Claim 15 (depends on 10) The communication system according to claim 10, wherein an external transmit signal is transmitted by an external transmitter. ### Claim 16 (depends on 15) The communication system according to claim 15, wherein the first transmit signal dominates the external transmit signal. ### Claim 17 (depends on 15) The communication system according to claim 15, wherein the first transmitter is a jammer. ### Claim 18 (depends on 15) The communication system according to claim 15, wherein the first transmitter is a part of a DAS system. ### Claim 19 (depends on 15) The communication system according to claim 15, wherein the first transmit signal is a jamming signal. ### Claim 20 (depends on 15) The communication system according to claim 15, wherein the first transmit signal is a MAS signal.